Merge branch 'main' into issue-3911issue-3911

117 files changed, 1727 insertions, 2663 deletions

diff --git a/app/controllers/accessibility/forms.php b/app/controllers/accessibility/forms.php
index f4f9adf..e240a6c 100644
--- a/app/controllers/accessibility/forms.php
+++ b/app/controllers/accessibility/forms.php
@@ -3,6 +3,21 @@ class Accessibility_FormsController extends StudipController
 {
     protected $with_session = true;
 
+    public function before_filter(&$action, &$args)
+    {
+        parent::before_filter($action, $args);
+
+        if (
+            Config::get()->REPORT_BARRIER_MODE === 'off'
+            || (
+                Config::get()->REPORT_BARRIER_MODE === 'logged-in'
+                && !User::findCurrent()
+            )
+        ) {
+            throw new AccessDeniedException();
+        }
+    }
+
     public function report_barrier_action()
     {
         PageLayout::setTitle(_('Barriere melden'));
@@ -131,6 +146,9 @@ class Accessibility_FormsController extends StudipController
         }
 
         $this->form->addPart($personal_data_part);
+
+        $this->form->addPart(new \Studip\Forms\Captcha());
+
         $this->form->setSaveButtonText(_('Barriere melden'));
         $this->form->setSaveButtonName('report');
         $this->form->setURL($this->report_barrierURL());
diff --git a/app/controllers/activityfeed.php b/app/controllers/activityfeed.php
index 2f93aa1..ee83826 100644
--- a/app/controllers/activityfeed.php
+++ b/app/controllers/activityfeed.php
@@ -53,7 +53,7 @@ class ActivityfeedController extends AuthenticatedController
         unset($modules[Context::INSTITUTE]['participants']);
         unset($modules[Context::INSTITUTE]['schedule']);
 
-        $standard_plugins = PluginManager::getInstance()->getPlugins("StandardPlugin");
+        $standard_plugins = PluginManager::getInstance()->getPlugins(StandardPlugin::class);
         foreach ($standard_plugins as $plugin) {
             if ($plugin instanceof ActivityProvider) {
                 $modules[Context::COURSE][$plugin->getPluginName()] = $plugin->getPluginName();
@@ -67,7 +67,7 @@ class ActivityfeedController extends AuthenticatedController
             'blubber'      => _('Blubber'),
         ];
 
-        $homepage_plugins = PluginEngine::getPlugins('HomepagePlugin');
+        $homepage_plugins = PluginEngine::getPlugins(HomepagePlugin::class);
         foreach ($homepage_plugins as $plugin) {
             if ($plugin->isActivated($GLOBALS['user']->id, 'user')) {
                 if ($plugin instanceof ActivityProvider) {
@@ -92,4 +92,193 @@ class ActivityfeedController extends AuthenticatedController
 
         PageLayout::setTitle(_('Aktivitäten konfigurieren'));
     }
+
+    public function load_action(): void
+    {
+        $user = User::findCurrent();
+
+        // failsafe einbauen - falls es keine älteren Aktivitäten mehr im System gibt, Abbruch!
+
+        $oldest_activity = \Studip\Activity\Activity::getOldestActivity();
+        $max_age = $oldest_activity ? $oldest_activity->mkdate : time();
+
+
+        $contexts = [];
+
+        // create system context
+        $system_context = new \Studip\Activity\SystemContext($user);
+        $contexts[] = $system_context;
+
+        $contexts[] = new \Studip\Activity\UserContext($user, $user);
+        $user->contacts->each(function ($another_user) use (&$contexts, $user) {
+            $contexts[] = new \Studip\Activity\UserContext($another_user, $user);
+        });
+
+        if (!in_array($user->perms, ['admin','root'])) {
+            // create courses and institutes context
+            foreach (\Course::findMany($user->course_memberships->pluck('seminar_id')) as $course) {
+                $contexts[] = new \Studip\Activity\CourseContext($course, $user);
+            }
+            foreach (\Institute::findMany($user->institute_memberships->pluck('institut_id')) as $institute) {
+                $contexts[] = new \Studip\Activity\InstituteContext($institute, $user);
+            }
+        }
+
+
+        // add filters
+        $filter = new \Studip\Activity\Filter();
+
+        $start = Request::int('start', strtotime('yesterday'));
+        $end   = Request::int('end',   time());
+
+
+        $scrollfrom = Request::int('scrollfrom', false);
+        $filtertype = Request::get('filtertype', '');
+
+        $objectType = Request::get('object_type');
+        $filter->setObjectType($objectType);
+
+        $objectId = Request::get('object_id');
+        $filter->setObjectId($objectId);
+
+        $context = Request::get('context_type');
+        $filter->setContext($context);
+
+        $contextId = Request::get('context_id');
+        $filter->setContextId($contextId);
+
+        if (!empty($filtertype)) {
+            $filter->setType(json_decode($filtertype));
+        }
+
+        if ($scrollfrom) {
+            // shorten "watch-window" by one second to prevent duplication of activities
+            $scrollfrom -= 1;
+
+            if ($scrollfrom > $max_age){
+                $end = $scrollfrom;
+                $start = strtotime('yesterday', $end);
+                $data = [];
+
+                $backtrack = 1;
+
+                while (empty($data)) {
+                    $filter->setStartDate($start);
+                    $filter->setEndDate($end);
+
+                    $data = $this->getStreamData($contexts, $filter);
+
+                    if ($start < $max_age) {
+                        break;
+                    }
+
+                    // move "watch-window" back one day at a time
+                    $end = $start - 1;
+                    $start = strtotime("-{$backtrack} days", $start);
+
+                    // enforce maximum "watch-window", currently 2 weeks
+                    $backtrack = min(14, $backtrack + 1);
+                }
+            } else {
+                $data = false;
+            }
+        } else {
+            $filter->setStartDate($start);
+            $filter->setEndDate($end);
+            $data = $this->getStreamData($contexts, $filter);
+        }
+
+        // set etag for preventing resending the same stuff over and over again
+        $etag = md5(serialize($data));
+        $this->response->add_header('ETag', '"' . $etag . '"');
+        if (isset($_SERVER['HTTP_IF_NONE_MATCH']) && $this->etagMatches($etag, $_SERVER['HTTP_IF_NONE_MATCH'])) {
+            $this->set_status(304);
+            $this->render_nothing();
+            return;
+        }
+        if (isset($_SERVER['HTTP_IF_MATCH']) && !$this->etagMatches($etag, $_SERVER['HTTP_IF_MATCH'])) {
+            $this->set_status(412);
+            $this->render_nothing();
+            return;
+        }
+
+        $this->render_json($data);
+    }
+
+    /**
+     *  private helper function to get stream data for given contexts and filter
+     *
+     * @param $contexts
+     * @param $filter
+     * @return array
+     */
+
+    private function getStreamData($contexts, $filter): array
+    {
+        $stream = new Studip\Activity\Stream($contexts, $filter);
+        $data = $stream->toArray();
+
+        foreach ($data as $key => $act) {
+            $actor = [
+                'type' => $act['actor_type'],
+                'id'   => $act['actor_id'],
+            ];
+
+            if ($act['actor_type'] == 'user') {
+                $a_user = \User::findFull($act['actor_id']);
+                $actor['details'] = $this->getMiniUser($a_user ?: new \User());
+            } elseif ($act['actor_type'] === 'anonymous') {
+                $actor['details'] = [
+                    'name' => _('Anonym'),
+                ];
+            }
+
+            unset($data[$key]['actor_type']);
+            unset($data[$key]['actor_id']);
+
+            $data[$key]['actor'] = $actor;
+        }
+
+        return $data;
+    }
+
+    private function getMiniUser(User $user): array
+    {
+        $avatar = \Avatar::getAvatar($user->id);
+
+        return [
+            'id'              => $user->id,
+            'name'            => $this->getNamesOfUser($user),
+            'avatar_small'    => $avatar->getURL(\Avatar::SMALL),
+            'avatar_medium'   => $avatar->getURL(\Avatar::MEDIUM),
+            'avatar_normal'   => $avatar->getURL(\Avatar::NORMAL),
+            'avatar_original' => $avatar->getURL(\Avatar::NORMAL)
+        ];
+    }
+
+    private function getNamesOfUser(User $user): array
+    {
+        return [
+            'username'  => $user->username,
+            'formatted' => $user->getFullName(),
+            'family'    => $user->nachname,
+            'given'     => $user->vorname,
+            'prefix'    => $user->title_front,
+            'suffix'    => $user->title_rear,
+        ];
+    }
+
+    // Helper method checking if a ETag value list includes the current ETag.
+    private function etagMatches(string $etag, string $list)
+    {
+        if ($list === '*') {
+            return true;
+        }
+
+        return in_array(
+            $etag,
+            preg_split('/\s*,\s*/', $list)
+        );
+    }
+
 }
diff --git a/app/controllers/admin/additional.php b/app/controllers/admin/additional.php
index a98da20..6f8f08c 100644
--- a/app/controllers/admin/additional.php
+++ b/app/controllers/admin/additional.php
@@ -30,6 +30,8 @@ class Admin_AdditionalController extends AuthenticatedController
             throw new AccessDeniedException(_("Sie haben keine Berechtigung diese " .
                     "Veranstaltung zu verändern."));
         }
+
+        Sidebar::get()->addWidget(new CourseManagementSelectWidget());
     }
 
     /**
diff --git a/app/controllers/admin/api.php b/app/controllers/admin/api.php
deleted file mode 100644
index 96adb65..0000000
--- a/app/controllers/admin/api.php
+++ /dev/null
@@ -1,210 +0,0 @@
-<?php
-/**
- *
- **/
-class Admin_ApiController extends AuthenticatedController
-{
-    /**
-     *
-     **/
-    public function before_filter(&$action, &$args)
-    {
-        parent::before_filter($action, $args);
-
-        require_once 'lib/bootstrap-api.php';
-
-        $GLOBALS['perm']->check('root');
-
-        Navigation::activateItem('/admin/config/api');
-        PageLayout::setTitle(_('API Verwaltung'));
-
-        $this->types = [
-            'website' => _('Website'),
-            'desktop' => _('Herkömmliches Desktopprogramm'),
-            'mobile'  => _('Mobile App')
-        ];
-
-        // Sidebar
-        $views = new ViewsWidget();
-        $views->addLink(_('Registrierte Applikationen'),
-                        $this->url_for('admin/api'))
-              ->setActive($action === 'index');
-        $views->addLink(_('Globale Zugriffseinstellungen'),
-                        $this->url_for('admin/api/permissions'))
-              ->setActive($action == 'permissions');
-        $views->addLink(_('Konfiguration'),
-                        $this->url_for('admin/api/config'))
-              ->setActive($action == 'config');
-        Sidebar::get()->addWidget($views);
-
-        $actions = new ActionsWidget();
-        $actions->addLink(_('Neue Applikation registrieren'),
-                          $this->url_for('admin/api/edit'),
-                          Icon::create('add', 'clickable'))
-                ->asDialog();
-        Sidebar::get()->addWidget($actions);
-    }
-
-    /**
-     *
-     **/
-    public function index_action()
-    {
-        $this->consumers = RESTAPI\Consumer\Base::findAll();
-        $this->routes = RESTAPI\Router::getInstance()->getRoutes(true);
-    }
-
-    /**
-     *
-     **/
-    public function render_keys($id)
-    {
-        $consumer = RESTAPI\Consumer\Base::find($id);
-
-        return [
-            'Consumer Key = ' . $consumer->auth_key,
-            'Consumer Secret = ' . $consumer->auth_secret,
-        ];
-    }
-
-    /**
-     *
-     **/
-    public function keys_action($id)
-    {
-        $details = $this->render_keys($id);
-
-        if (Request::isXhr()) {
-            $this->render_text(implode('<br>', $details));
-        } else {
-            PageLayout::postMessage(MessageBox::info(_('Die Schlüssel in den Details dieser Meldung sollten vertraulich behandelt werden!'), $details, true));
-            $this->redirect('admin/api/#' . $id);
-        }
-    }
-
-    /**
-     *
-     **/
-    public function edit_action($id = null)
-    {
-        $consumer = $id
-                  ? RESTAPI\Consumer\Base::find($id)
-                  : RESTAPI\Consumer\Base::create(Request::option('consumer_type') ?: 'oauth');
-
-        if (Request::submitted('store')) {
-            $errors = [];
-
-            $consumer->active      = (bool) Request::int('active');
-            $consumer->title       = Request::get('title');
-            $consumer->contact     = Request::get('contact');
-            $consumer->email       = Request::get('email');
-            $consumer->callback    = Request::get('callback');
-            $consumer->url         = Request::get('url');
-            $consumer->type        = Request::get('type') ?: null;
-            $consumer->commercial  = Request::int('commercial');
-            $consumer->notes       = Request::get('notes');
-            $consumer->description = Request::get('description');
-
-            if (!empty($errors)) {
-                $message = MessageBox::error(_('Folgende Fehler sind aufgetreten:'), $errors);
-                PageLayout::postMessage($message);
-                return;
-            }
-
-            $consumer->store();
-
-            if ($id) {
-                $message = MessageBox::success(_('Die Applikation wurde erfolgreich gespeichert.'));
-            } else {
-                $details  = $this->render_keys($consumer->id);
-                $message = MessageBox::success(_('Die Applikation wurde erfolgreich erstellt, die Schlüssel finden Sie in den Details dieser Meldung.'), $details, true);
-            }
-            PageLayout::postMessage($message);
-            $this->redirect('admin/api/index#' . $consumer->id);
-            return;
-        }
-
-        $this->consumer = $consumer;
-        $this->id = $id;
-    }
-
-    /**
-     *
-     **/
-    public function toggle_action($id, $state = null)
-    {
-        $consumer = RESTAPI\Consumer\Base::find($id);
-
-        $consumer->active = $state === null ? !$consumer->active : ($state === 'on');
-        $consumer->store();
-
-        $message = $state
-                 ? _('Die Applikation wurde erfolgreich aktiviert.')
-                 : _('Die Applikation wurde erfolgreich deaktiviert.');
-
-        PageLayout::postMessage(MessageBox::success($message));
-        $this->redirect('admin/api/#' . $consumer->id);
-    }
-
-    /**
-     *
-     **/
-    public function delete_action($id)
-    {
-        if (!Request::isPost()) {
-            throw new MethodNotAllowedException();
-        }
-        if ($consumer = RESTAPI\Consumer\Base::find($id)) {
-            $consumer->delete();
-
-            PageLayout::postSuccess(_('Die Applikation wurde erfolgreich gelöscht.'));
-        }
-        $this->redirect('admin/api');
-    }
-
-    /**
-     *
-     **/
-    public function permissions_action($consumer_id = null)
-    {
-        if (Request::submitted('store')) {
-            $perms       = Request::getArray('permission');
-            $permissions = RESTAPI\ConsumerPermissions::get($consumer_id ?: 'global');
-
-            foreach ($perms as $route => $methods) {
-                foreach ($methods as $method => $granted) {
-                    $permissions->set(urldecode($route), urldecode($method), (bool)$granted, true);
-                }
-            }
-
-            $permissions->store();
-
-            PageLayout::postMessage(MessageBox::success(_('Die Zugriffsberechtigungen wurden erfolgreich gespeichert')));
-            $this->redirect($consumer_id ? 'admin/api' : 'admin/api/permissions');
-            return;
-        }
-
-        $title = $consumer_id ? _('Zugriffsberechtigungen') : _('Globale Zugriffsberechtigungen');
-        $title .= ' - ' . PageLayout::getTitle();
-        PageLayout::setTitle($title);
-
-        $this->consumer_id = $consumer_id;
-        $this->router      = RESTAPI\Router::getInstance();
-        $this->routes      = $this->router->getRoutes(true, false);
-        $this->permissions = RESTAPI\ConsumerPermissions::get($consumer_id ?: 'global');
-        $this->global      = $consumer_id ? RESTAPI\ConsumerPermissions::get('global') : false;
-    }
-
-    public function config_action()
-    {
-        $this->config = Config::get();
-
-        if (Request::isPost()) {
-            $this->config->store('API_ENABLED', Request::int('active', 0));
-            $this->config->store('API_OAUTH_AUTH_PLUGIN', Request::option('auth'));
-
-            PageLayout::postMessage(MessageBox::success(_('Die Einstellungen wurden gespeichert.')));
-            $this->redirect('admin/api/config');
-        }
-    }
-}
diff --git a/app/controllers/admin/cache.php b/app/controllers/admin/cache.php
index 329aab7..c016af5 100644
--- a/app/controllers/admin/cache.php
+++ b/app/controllers/admin/cache.php
@@ -81,11 +81,10 @@ class Admin_CacheController extends AuthenticatedController
 
     /**
      * Fetches necessary configuration for given cache type.
-     *
-     * @param string $className
      */
-    public function get_config_action($className)
+    public function get_config_action()
     {
+        $className = Request::get('cache');
         $type = CacheType::findOneByClass_name($className);
 
         $this->render_json($type->class_name::getConfig());
@@ -111,7 +110,7 @@ class Admin_CacheController extends AuthenticatedController
         // Store settings to global config.
         if (Config::get()->store('SYSTEMCACHE', $settings)) {
             PageLayout::postSuccess(_('Die Einstellungen wurden gespeichert.'));
-            StudipCacheFactory::unconfigure();
+            \Studip\Cache\Factory::unconfigure();
         }
 
         $this->relocate('admin/cache/settings');
@@ -122,7 +121,7 @@ class Admin_CacheController extends AuthenticatedController
      */
     public function flush_action()
     {
-        $cache = StudipCacheFactory::getCache();
+        $cache = \Studip\Cache\Factory::getCache();
         $cache->flush();
 
         PageLayout::postSuccess(_('Die Inhalte des Caches wurden gelöscht.'));
@@ -135,7 +134,7 @@ class Admin_CacheController extends AuthenticatedController
      */
     public function stats_action()
     {
-        $cache = StudipCacheFactory::getCache();
+        $cache = \Studip\Cache\Factory::getCache();
 
         $this->stats = $cache->getStats();
     }
diff --git a/app/controllers/admin/courseplanning.php b/app/controllers/admin/courseplanning.php
index b8971e2..44b372d 100644
--- a/app/controllers/admin/courseplanning.php
+++ b/app/controllers/admin/courseplanning.php
@@ -82,7 +82,7 @@ class Admin_CourseplanningController extends AuthenticatedController
         foreach ($this->events as $event) {
             $start_date_time = explode('T', $event['start']);
             $time_elements = explode(':', $start_date_time[1]);
-            if (!$event['comform'] || $time_elements[0] % 2) {
+            if (!$event['conform'] || $time_elements[0] % 2) {
                 Sidebar::get()->getWidget('actions')->addLink(
                     _('Veranstaltungen außerhalb des Rasters'),
                     $this->nonconformURL(),
diff --git a/app/controllers/admin/courses.php b/app/controllers/admin/courses.php
index 6f9312d..5f60442 100644
--- a/app/controllers/admin/courses.php
+++ b/app/controllers/admin/courses.php
@@ -22,6 +22,7 @@
  * @category    Stud.IP
  * @since       3.1
  */
+
 require_once 'lib/meine_seminare_func.inc.php';
 require_once 'lib/object.inc.php';
 require_once 'lib/archiv.inc.php'; //for lastActivity in getCourses() method
@@ -293,7 +294,7 @@ class Admin_CoursesController extends AuthenticatedController
         PageLayout::setTitle(_('Verwaltung von Veranstaltungen und Einrichtungen'));
         // Add admission functions.
         PageLayout::addScript('studip-admission.js');
-        $this->max_show_courses = 500;
+        $this->max_show_courses = Config::get()->MAX_SHOW_ADMIN_COURSES;
     }
 
     /**
@@ -322,6 +323,9 @@ class Admin_CoursesController extends AuthenticatedController
         $institut_id = $configuration->MY_INSTITUTES_DEFAULT && $configuration->MY_INSTITUTES_DEFAULT !== 'all'
                      ? $configuration->MY_INSTITUTES_DEFAULT
                      : null;
+        if ($configuration->MY_INSTITUTES_INCLUDE_CHILDREN) {
+            $institut_id .= '_withinst';
+        }
 
         $filters = array_merge(
             array_merge(...PluginEngine::sendMessage(AdminCourseWidgetPlugin::class, 'getFilters')),
@@ -375,14 +379,14 @@ class Admin_CoursesController extends AuthenticatedController
         }
         PluginEngine::sendMessage(AdminCourseWidgetPlugin::class, 'applyFilters', $filter);
 
-        $count = $filter->countCourses();
-        if ($count > $this->max_show_courses && !Request::submitted('without_limit')) {
-            $this->render_json([
-                'count' => $count
-            ]);
+        try {
+            $courses = $filter->fetchCourses(
+                Request::bool('without_limit') ? null: $this->max_show_courses
+            );
+        } catch (OverflowException $e) {
+            $this->render_json(['count' => (int) $e->getMessage()]);
             return;
         }
-        $courses = AdminCourseFilter::get()->getCourses();
 
         $data = [
             'data' => []
@@ -417,7 +421,7 @@ class Admin_CoursesController extends AuthenticatedController
                 }
             }
         }
-        $tf = new Flexi_TemplateFactory($GLOBALS['STUDIP_BASE_PATH'] . '/app/views');
+        $tf = new Flexi\Factory($GLOBALS['STUDIP_BASE_PATH'] . '/app/views');
         switch ($GLOBALS['user']->cfg->MY_COURSES_ACTION_AREA) {
             case 1:
             case 2:
@@ -487,12 +491,12 @@ class Admin_CoursesController extends AuthenticatedController
                     ]);
                 break;
             default:
-                foreach (PluginManager::getInstance()->getPlugins('AdminCourseAction') as $plugin) {
+                foreach (PluginManager::getInstance()->getPlugins(AdminCourseAction::class) as $plugin) {
                     if ($GLOBALS['user']->cfg->MY_COURSES_ACTION_AREA === get_class($plugin)) {
                         $multimode = $plugin->useMultimode();
                         if ($multimode) {
                             $data['buttons_top'] = '<label>'._('Alle auswählen').'<input type="checkbox" data-proxyfor=".course-admin td:last-child :checkbox"></label>';
-                            if ($multimode instanceof Flexi_Template) {
+                            if ($multimode instanceof Flex\Template) {
                                 $data['buttons_bottom'] = $multimode->render();
                             } elseif ($multimode instanceof \Studip\Button) {
                                 $data['buttons_bottom'] = (string) $multimode;
@@ -531,14 +535,60 @@ class Admin_CoursesController extends AuthenticatedController
             'institut_id'    => 'MY_INSTITUTES_DEFAULT',
         ];
 
+        if (!empty($filters['institut_id'])) {
+            $config->store(
+                'MY_INSTITUTES_INCLUDE_CHILDREN',
+                str_contains($filters['institut_id'], '_') ? 1 : 0
+            );
+            if ($config->MY_INSTITUTES_INCLUDE_CHILDREN) {
+                $filters['institut_id'] = substr($filters['institut_id'], 0, strpos($filters['institut_id'], '_'));
+            }
+        }
+
         foreach ($mapping as $key => $field) {
             if (isset($filters[$key])) {
                 $config->store($field, $filters[$key]);
             }
-
             unset($filters[$key]);
         }
 
+        if ($config->ADMIN_COURSES_TEACHERFILTER) {
+            if (!$config->MY_INSTITUTES_DEFAULT) {
+                $config->delete('ADMIN_COURSES_TEACHERFILTER');
+            } else {
+                $include_children = $GLOBALS['user']->cfg->MY_INSTITUTES_INCLUDE_CHILDREN ? ' OR Institute.fakultaets_id = :institut_id ' : '';
+
+                $exists = InstituteMember::countBySQL("INNER JOIN `Institute` USING (`Institut_id`) WHERE `user_inst`.`user_id` = :user_id AND (`Institute`.`Institut_id` = :institut_id $include_children) AND `user_inst`.`inst_perms` = 'dozent' ", [
+                    'user_id' => $config->ADMIN_COURSES_TEACHERFILTER,
+                    'institut_id' => $config->MY_INSTITUTES_DEFAULT
+                ]) > 0;
+                if (!$exists) {
+                    $config->delete('ADMIN_COURSES_TEACHERFILTER');
+                }
+            }
+        }
+        if ($config->MY_COURSES_SELECTED_STGTEIL) {
+            if (!$config->MY_INSTITUTES_DEFAULT) {
+                $config->delete('MY_COURSES_SELECTED_STGTEIL');
+            } else {
+                $statement = DBManager::get()->prepare("
+                    SELECT 1
+                    FROM `mvv_stg_stgteil`
+                        INNER JOIN `mvv_studiengang` ON (`mvv_stg_stgteil`.`studiengang_id` = `mvv_studiengang`.`studiengang_id`)
+                    WHERE `mvv_studiengang`.`institut_id` = :institut_id
+                        AND `mvv_stg_stgteil`.`stgteil_id` = :stgteil_id
+                ");
+                $statement->execute([
+                    'institut_id' => $config->MY_INSTITUTES_DEFAULT,
+                    'stgteil_id' => $config->MY_COURSES_SELECTED_STGTEIL
+                ]);
+                $exists = (bool) $statement->fetch(PDO::FETCH_COLUMN);
+                if (!$exists) {
+                    $config->delete('MY_COURSES_SELECTED_STGTEIL');
+                }
+            }
+        }
+
         // Datafield filters
         $activeSidebarElements = $this->getActiveElements();
 
@@ -576,19 +626,19 @@ class Admin_CoursesController extends AuthenticatedController
         if (in_array('name', $activated_fields)) {
             $params = tooltip2(_('Veranstaltungsdetails anzeigen'));
             $params['style'] = 'cursor: pointer';
-            $d['name'] = '<a href="'.URLHelper::getLink('seminar_main.php', ['auswahl' => $course->id]).'">'
+            $d['name'] = '<a href="'.URLHelper::getLink('dispatch.php/course/basicdata/view', ['cid' => $course->id]).'">'
                 . htmlReady($course->name)
                 .'</a> '
                 .'<a href="'.URLHelper::getLink('dispatch.php/course/details/index/'. $course->id).'" data-dialog><button class="undecorated">'.Icon::create('info-circle', Icon::ROLE_INACTIVE)->asImg($params).'</button></a> '
                 .(!$course->visible ? _('(versteckt)') : '');
         }
         if (in_array('number', $activated_fields)) {
-            $d['number'] = '<a href="'.URLHelper::getLink('seminar_main.php', ['auswahl' => $course->id]).'">'
+            $d['number'] = '<a href="'.URLHelper::getLink('dispatch.php/course/basicdata/view', ['cid' => $course->id]).'">'
                 .$course->veranstaltungsnummer
                 .'</a>';
         }
         if (in_array('avatar', $activated_fields)) {
-            $d['avatar'] = '<a href="'.URLHelper::getLink('seminar_main.php', ['auswahl' => $course->id]).'">'
+            $d['avatar'] = '<a href="'.URLHelper::getLink('dispatch.php/course/basicdata/view', ['cid' => $course->id]).'">'
                 .CourseAvatar::getAvatar($course->getId())->getImageTag(Avatar::SMALL, ['title' => $course->name])
                 ."</a>";
         }
@@ -604,6 +654,7 @@ class Admin_CoursesController extends AuthenticatedController
         }
         if (in_array('semester', $activated_fields)) {
             $d['semester'] = $course->semester_text;
+            $d['semester_sort'] = $course->start_semester ? $course->start_semester->beginn : 0;
         }
         if (in_array('institute', $activated_fields)) {
             $d['institute'] = $course->home_institut ? $course->home_institut->name : $course->institute;
@@ -620,7 +671,7 @@ class Admin_CoursesController extends AuthenticatedController
         }
         if (in_array('members', $activated_fields)) {
             $d['members'] = '<a href="'.URLHelper::getLink('dispatch.php/course/members', ['cid' => $course->id]).'">'
-                .$course->getNumParticipants()
+                .$course->countMembersWithStatus('user autor')
                 .'</a>';
         }
         if (in_array('waiting', $activated_fields)) {
@@ -663,15 +714,18 @@ class Admin_CoursesController extends AuthenticatedController
             $d['last_activity_raw'] = $last_activity;
         }
 
-        foreach (PluginManager::getInstance()->getPlugins('AdminCourseContents') as $plugin) {
+        foreach (PluginManager::getInstance()->getPlugins(AdminCourseContents::class) as $plugin) {
             foreach ($plugin->adminAvailableContents() as $index => $label) {
                 if (in_array($plugin->getPluginId() . '_' . $index, $activated_fields)) {
                     $content = $plugin->adminAreaGetCourseContent($course, $index);
-                    $d[$plugin->getPluginId()."_".$index] = $content instanceof Flexi_Template ? $content->render() : $content;
+                    if ($content instanceof Flexi\Template) {
+                        $content = $content->render();
+                    }
+                    $d[$plugin->getPluginId()."_".$index] = $content;
                 }
             }
         }
-        $tf = new Flexi_TemplateFactory($GLOBALS['STUDIP_BASE_PATH'].'/app/views');
+        $tf = new Flexi\Factory($GLOBALS['STUDIP_BASE_PATH'].'/app/views');
 
         switch ($GLOBALS['user']->cfg->MY_COURSES_ACTION_AREA) {
             case 1:
@@ -789,10 +843,13 @@ class Admin_CoursesController extends AuthenticatedController
                 $d['action'] = $template->render();
                 break;
             default:
-                foreach (PluginManager::getInstance()->getPlugins('AdminCourseAction') as $plugin) {
+                foreach (PluginManager::getInstance()->getPlugins(AdminCourseAction::class) as $plugin) {
                     if ($GLOBALS['user']->cfg->MY_COURSES_ACTION_AREA === get_class($plugin)) {
                         $output = $plugin->getAdminCourseActionTemplate($course->getId());
-                        $d['action'] = $output instanceof Flexi_Template ? $output->render() : (string) $output;
+                        if ($output instanceof Flexi\Template) {
+                            $output = $output->render();
+                        }
+                        $d['action'] = (string) $output;
                         break;
                     }
                 }
@@ -981,14 +1038,14 @@ class Admin_CoursesController extends AuthenticatedController
                     $row['institute'] = $course->home_institut ? (string) $course->home_institut['name'] : $course['institut_id'];
                 }
 
-                foreach (PluginManager::getInstance()->getPlugins('AdminCourseContents') as $plugin) {
+                foreach (PluginManager::getInstance()->getPlugins(AdminCourseContents::class) as $plugin) {
                     foreach ($plugin->adminAvailableContents() as $index => $label) {
                         if (in_array($plugin->getPluginId() . "_" . $index, $filter_config)) {
                             $content = $plugin->adminAreaGetCourseContent($course, $index);
-                            $row[$plugin->getPluginId() . "_" . $index] = strip_tags(is_a($content, 'Flexi_Template')
-                                ? $content->render()
-                                : $content
-                            );
+                            if ($content instanceof Flexi\Template) {
+                                $content = $content->render();
+                            }
+                            $row[$plugin->getPluginId() . "_" . $index] = strip_tags($content);
                         }
                     }
                 }
@@ -1000,7 +1057,7 @@ class Admin_CoursesController extends AuthenticatedController
             foreach ($filter_config as $index) {
                 $captions[$index] = $view_filters[$index];
             }
-            foreach (PluginManager::getInstance()->getPlugins('AdminCourseContents') as $plugin) {
+            foreach (PluginManager::getInstance()->getPlugins(AdminCourseContents::class) as $plugin) {
                 foreach ($plugin->adminAvailableContents() as $index => $label) {
                     if (in_array($plugin->getPluginId() . "_" . $index, $filter_config)) {
                         $captions[$plugin->getPluginId() . "_" . $index] = $label;
@@ -1398,7 +1455,7 @@ class Admin_CoursesController extends AuthenticatedController
 
         ksort($actions);
 
-        foreach (PluginManager::getInstance()->getPlugins('AdminCourseAction') as $plugin) {
+        foreach (PluginManager::getInstance()->getPlugins(AdminCourseAction::class) as $plugin) {
             $actions[get_class($plugin)] = [
                 'name'      => $plugin->getPluginName(),
                 'title'     => $plugin->getPluginName(),
@@ -1438,7 +1495,7 @@ class Admin_CoursesController extends AuthenticatedController
             'contents'      => _('Inhalt'),
             'last_activity' => _('Letzte Aktivität'),
         ];
-        foreach (PluginManager::getInstance()->getPlugins('AdminCourseContents') as $plugin) {
+        foreach (PluginManager::getInstance()->getPlugins(AdminCourseContents::class) as $plugin) {
             foreach ($plugin->adminAvailableContents() as $index => $label) {
                 $views[$plugin->getPluginId() . "_" . $index] = $label;
             }
@@ -1446,169 +1503,6 @@ class Admin_CoursesController extends AuthenticatedController
         return $views;
     }
 
-    /**
-     * Returns all courses matching set criteria.
-     *
-     * @param array $params Additional parameters
-     * @param bool $display_all : boolean should we show all courses or check for a limit of 500 courses?
-     * @return array of courses
-     */
-    private function getCourses($params = [], $display_all = false)
-    {
-        // Init
-        if ($GLOBALS['user']->cfg->MY_INSTITUTES_DEFAULT === "all") {
-            $inst = new SimpleCollection($this->insts);
-            $inst->filter(function ($a) use (&$inst_ids) {
-                $inst_ids[] = $a->Institut_id;
-            });
-        } else {
-            //We must check, if the institute ID belongs to a faculty
-            //and has the string _i appended to it.
-            //In that case we must display the courses of the faculty
-            //and all its institutes.
-            //Otherwise we just display the courses of the faculty.
-
-            $inst_id = $GLOBALS['user']->cfg->MY_INSTITUTES_DEFAULT;
-
-            $institut = new Institute($inst_id);
-
-            if (!$institut->isFaculty() || $GLOBALS['user']->cfg->MY_INSTITUTES_INCLUDE_CHILDREN) {
-                // If the institute is not a faculty or the child insts are included,
-                // pick the institute IDs of the faculty/institute and of all sub-institutes.
-                $inst_ids[] = $inst_id;
-                if ($institut->isFaculty()) {
-                    foreach ($institut->sub_institutes->pluck('Institut_id') as $institut_id) {
-                        $inst_ids[] = $institut_id;
-                    }
-                }
-            } else {
-                // If the institute is a faculty and the child insts are not included,
-                // pick only the institute id of the faculty:
-                $inst_ids[] = $inst_id;
-            }
-        }
-
-        $active_elements = $this->getActiveElements();
-
-        $filter = AdminCourseFilter::get(true);
-
-        if ($params['datafields']) {
-            foreach ($params['datafields'] as $field_id => $value) {
-                $datafield = DataField::find($field_id);
-                if ($datafield) {
-                    //enable filtering by datafield values:
-                    //and use the where-clause for each datafield:
-                    $filter->settings['query']['joins']['de_'.$field_id] = [
-                        'table' => "datafields_entries",
-                        'join' => "LEFT JOIN",
-                        'on' => "seminare.seminar_id = de_".$field_id.".range_id"
-                    ];
-                    $filter->where("(de_".$field_id.".datafield_id = :fieldId_".$field_id." "
-                        . "AND de_".$field_id.".content = :fieldValue_".$field_id.") "
-                        . ($datafield['default_value'] == $value ? " OR (de_".$field_id.".content IS NULL)" : "")." ",
-                        [
-                            'fieldId_'.$field_id => $field_id,
-                            'fieldValue_'.$field_id => $value
-                        ]
-                    );
-                }
-            }
-        }
-
-        $filter->where("sem_classes.studygroup_mode = '0'");
-
-        // Get only children of given course
-        if (!empty($params['parent_course'])) {
-            $filter->where("parent_course = :parent",
-                [
-                    'parent' => $params['parent_course']
-                ]
-            );
-        }
-
-        if ($active_elements['semester'] && is_object($this->semester)) {
-            $filter->filterBySemester($this->semester->getId());
-        }
-        if ($active_elements['courseType'] && $params['typeFilter'] && $params['typeFilter'] !== "all") {
-            $parts = explode('_', $params['typeFilter']);
-            $class_filter = $parts[0];
-            $type_filter = $parts[1] ?? null;
-            if (!$type_filter && !empty($GLOBALS['SEM_CLASS'][$class_filter])) {
-                $type_filter = array_keys($GLOBALS['SEM_CLASS'][$class_filter]->getSemTypes());
-            }
-            $filter->filterByType($type_filter);
-        }
-        if ($active_elements['search'] && $GLOBALS['user']->cfg->ADMIN_COURSES_SEARCHTEXT) {
-            $filter->filterBySearchString($GLOBALS['user']->cfg->ADMIN_COURSES_SEARCHTEXT);
-        }
-        if ($active_elements['teacher'] && $GLOBALS['user']->cfg->ADMIN_COURSES_TEACHERFILTER && ($GLOBALS['user']->cfg->ADMIN_COURSES_TEACHERFILTER !== "all")) {
-            $filter->filterByDozent($GLOBALS['user']->cfg->ADMIN_COURSES_TEACHERFILTER);
-        }
-        if ($active_elements['institute']) {
-            $filter->filterByInstitute($inst_ids);
-        }
-        if ($GLOBALS['user']->cfg->MY_COURSES_SELECTED_STGTEIL && $GLOBALS['user']->cfg->MY_COURSES_SELECTED_STGTEIL !== 'all') {
-            $filter->filterByStgTeil($GLOBALS['user']->cfg->MY_COURSES_SELECTED_STGTEIL);
-        }
-        if ($params['sortby'] === "status") {
-            $filter->orderBy(sprintf('sem_classes.name %s, sem_types.name %s, VeranstaltungsNummer %s', $params['sortFlag'], $params['sortFlag'], $params['sortFlag']), $params['sortFlag']);
-        } elseif ($params['sortby'] === 'institute') {
-            $filter->orderBy('Institute.Name', $params['sortFlag']);
-        } elseif ($params['sortby']) {
-            $filter->orderBy($params['sortby'], $params['sortFlag']);
-        }
-        $filter->storeSettings();
-        $this->count_courses = $filter->countCourses();
-        if ($this->count_courses && ($this->count_courses <= $filter->max_show_courses || $display_all)) {
-            $courses = $filter->getCourses();
-        } else {
-            return [];
-        }
-
-        $seminars = [];
-        if (!empty($courses)) {
-            foreach ($courses as $seminar_id => $seminar) {
-                $seminars[$seminar_id] = $seminar[0];
-                $seminars[$seminar_id]['seminar_id'] = $seminar_id;
-                $seminars[$seminar_id]['obj_type'] = 'sem';
-                $dozenten = $this->getTeacher($seminar_id);
-                $seminars[$seminar_id]['dozenten'] = $dozenten;
-
-                if (in_array('contents', $params['view_filter'])) {
-                    $tools = new SimpleCollection(ToolActivation::findbyRange_id($seminar_id, "ORDER BY position"));
-                    $visit_data = get_objects_visits([$seminar_id], 0, null, null, $tools->pluck('plugin_id'));
-                    $seminars[$seminar_id]['visitdate'] = $visit_data[$seminar_id][0]['visitdate'];
-                    $seminars[$seminar_id]['last_visitdate'] = $visit_data[$seminar_id][0]['last_visitdate'];
-                    $seminars[$seminar_id]['tools'] = $tools;
-                    $seminars[$seminar_id]['navigation'] = MyRealmModel::getAdditionalNavigations(
-                        $seminar_id,
-                        $seminars[$seminar_id],
-                        $seminars[$seminar_id]['sem_class'] ?? null,
-                        $GLOBALS['user']->id,
-                        $visit_data[$seminar_id]
-                    );
-                }
-                //add last activity column:
-                if (in_array('last_activity', $params['view_filter'])) {
-                    $seminars[$seminar_id]['last_activity'] = lastActivity($seminar_id);
-                }
-                if ((int)$this->selected_action === 17) {
-                    $seminars[$seminar_id]['admission_locked'] = false;
-                    if ($seminar[0]['course_set']) {
-                        $set = new CourseSet($seminar[0]['course_set']);
-                        if (!is_null($set) && $set->hasAdmissionRule('LockedAdmission')) {
-                            $seminars[$seminar_id]['admission_locked'] = 'locked';
-                        } else {
-                            $seminars[$seminar_id]['admission_locked'] = 'disable';
-                        }
-                        unset($set);
-                    }
-                }
-            }
-        }
-
-        return $seminars;
-    }
 
     /**
      * Returns the teacher for a given cours
@@ -1650,6 +1544,7 @@ class Admin_CoursesController extends AuthenticatedController
                     $institut['Institut_id'],
                     (!$institut['is_fak'] ? ' ' : '') . $institut['Name'],
                     $GLOBALS['user']->cfg->MY_INSTITUTES_DEFAULT === $institut['Institut_id']
+                        && !$GLOBALS['user']->cfg->MY_INSTITUTES_INCLUDE_CHILDREN
                 );
 
             //check if the institute is a faculty.
@@ -1662,7 +1557,8 @@ class Admin_CoursesController extends AuthenticatedController
                     new SelectElement(
                         $institut['Institut_id'] . '_withinst', //_withinst = with institutes
                         ' ' . $institut['Name'] . ' +' . _('Institute'),
-                        ($GLOBALS['user']->cfg->MY_INSTITUTES_DEFAULT === $institut['Institut_id'] && $GLOBALS['user']->cfg->MY_INSTITUTES_INCLUDE_CHILDREN)
+                        $GLOBALS['user']->cfg->MY_INSTITUTES_DEFAULT === $institut['Institut_id']
+                            && $GLOBALS['user']->cfg->MY_INSTITUTES_INCLUDE_CHILDREN
                     );
             }
         }
@@ -1695,6 +1591,9 @@ class Admin_CoursesController extends AuthenticatedController
     private function getStgteilSelector($institut_id = null)
     {
         $institut_id = $institut_id ?: $GLOBALS['user']->cfg->MY_INSTITUTES_DEFAULT;
+        if (str_contains($institut_id, '_')) {
+            $institut_id = substr($institut_id, 0, strpos($institut_id, '_'));
+        }
         $stgteile = StudiengangTeil::getAllEnriched('fach_name', 'ASC', ['mvv_fach_inst.institut_id' => $institut_id]);
         $list = [];
         if (!$institut_id || $institut_id === 'all') {
@@ -1782,27 +1681,42 @@ class Admin_CoursesController extends AuthenticatedController
      */
     private function getTeacherWidget($institut_id = null)
     {
-        $institut_id = $institut_id ?: $GLOBALS['user']->cfg->MY_INSTITUTES_DEFAULT;
-        $teachers = DBManager::get()->fetchAll("
+        if ($institut_id) {
+            if (str_contains($institut_id, '_')) {
+                $institut_id = substr($institut_id, 0, strpos($institut_id, '_'));
+                $GLOBALS['user']->cfg->store('MY_INSTITUTES_INCLUDE_CHILDREN', 1);
+            } else {
+                $GLOBALS['user']->cfg->store('MY_INSTITUTES_INCLUDE_CHILDREN', 0);
+            }
+        } else {
+            $institut_id = $GLOBALS['user']->cfg->MY_INSTITUTES_DEFAULT;
+        }
+
+        $teachers = [];
+        $include_children = $GLOBALS['user']->cfg->MY_INSTITUTES_INCLUDE_CHILDREN ? ' OR Institute.fakultaets_id = :institut_id ' : '';
+
+        if ($institut_id) {
+            $teachers = DBManager::get()->fetchAll("
                 SELECT auth_user_md5.*, user_info.*
                 FROM auth_user_md5
                     LEFT JOIN user_info ON (auth_user_md5.user_id = user_info.user_id)
                     INNER JOIN user_inst ON (user_inst.user_id = auth_user_md5.user_id)
                     INNER JOIN Institute ON (Institute.Institut_id = user_inst.Institut_id)
-                WHERE (Institute.Institut_id = :institut_id OR Institute.fakultaets_id = :institut_id)
-                    AND auth_user_md5.perms = 'dozent'
+                WHERE (Institute.Institut_id = :institut_id $include_children)
+                    AND user_inst.inst_perms = 'dozent'
+                GROUP BY auth_user_md5.user_id
                 ORDER BY auth_user_md5.Nachname ASC, auth_user_md5.Vorname ASC
             ", [
                 'institut_id' => $institut_id
             ],
-            function ($data) {
-                $ret['user_id'] = $data['user_id'];
-                unset($data['user_id']);
-                $ret['fullname'] = User::build($data)->getFullName("full_rev");
-                return $ret;
-            }
-        );
-
+                function ($data) {
+                    $ret['user_id'] = $data['user_id'];
+                    unset($data['user_id']);
+                    $ret['fullname'] = User::build($data)->getFullName("full_rev");
+                    return $ret;
+                }
+            );
+        }
 
         $list = [];
         if (!$institut_id || $institut_id === 'all') {
diff --git a/app/controllers/admin/cronjobs/schedules.php b/app/controllers/admin/cronjobs/schedules.php
index 294d78d..929ae29 100644
--- a/app/controllers/admin/cronjobs/schedules.php
+++ b/app/controllers/admin/cronjobs/schedules.php
@@ -29,7 +29,7 @@ class Admin_Cronjobs_SchedulesController extends AuthenticatedController
         if (empty($_SESSION['cronjob-filter'])) {
             $_SESSION['cronjob-filter'] = [
                 'where'  => '1',
-                'values' => array_fill_keys(['type', 'status', 'task_id'], null),
+                'values' => array_fill_keys(['status', 'task_id'], null),
             ];
         }
 
@@ -102,9 +102,6 @@ class Admin_Cronjobs_SchedulesController extends AuthenticatedController
         $filter     = array_filter(Request::optionArray('filter'));
         $conditions = [];
 
-        if (!empty($filter['type'])) {
-            $conditions[] = "type = " . DBManager::get()->quote($filter['type']);
-        }
         if (!empty($filter['status'])) {
             $active = (int)($filter['status'] === 'active');
             $conditions[] = "active = " . DBManager::get()->quote($active);
@@ -130,7 +127,6 @@ class Admin_Cronjobs_SchedulesController extends AuthenticatedController
         if (Request::submitted('store')) {
             $parameters = Request::getArray('parameters');
 
-            $schedule->priority    = Request::option('priority', 'normal');
             $schedule->title       = Request::get('title');
             $schedule->description = Request::get('description');
             $schedule->active      = Request::int('active', 0);
@@ -138,27 +134,20 @@ class Admin_Cronjobs_SchedulesController extends AuthenticatedController
                 $schedule->task_id = Request::option('task_id');
             }
             $schedule->parameters  = $parameters[$schedule->task_id];
-            $schedule->type        = Request::option('type') === 'once'
-                                   ? 'once'
-                                   : 'periodic';
-
-            if ($schedule->type === 'once') {
-                $temp = Request::getArray('once');
-                $schedule->next_execution = strtotime($temp['date'] . ' ' . $temp['time']);
-            } else {
-                $temp = Request::getArray('periodic');
-                $schedule->minute      = $this->extractCronItem($temp['minute']);
-                $schedule->hour        = $this->extractCronItem($temp['hour']);
-                $schedule->day         = $this->extractCronItem($temp['day']);
-                $schedule->month       = $this->extractCronItem($temp['month']);
-                $schedule->day_of_week = mb_strlen($temp['day_of_week']['value'])
-                                       ? (int) $temp['day_of_week']['value']
-                                       : null;
-
-                if ($schedule->active) {
-                    $schedule->next_execution = $schedule->calculateNextExecution();
-                }
+
+            $temp = Request::getArray('periodic');
+            $schedule->minute      = $this->extractCronItem($temp['minute']);
+            $schedule->hour        = $this->extractCronItem($temp['hour']);
+            $schedule->day         = $this->extractCronItem($temp['day']);
+            $schedule->month       = $this->extractCronItem($temp['month']);
+            $schedule->day_of_week = mb_strlen($temp['day_of_week']['value'])
+                                   ? (int) $temp['day_of_week']['value']
+                                   : null;
+
+            if ($schedule->active) {
+                $schedule->next_execution = $schedule->calculateNextExecution();
             }
+
             $schedule->store();
 
             PageLayout::postSuccess(_('Die Änderungen wurden gespeichert.'));
diff --git a/app/controllers/admin/datafields.php b/app/controllers/admin/datafields.php
index bf390c9..6019a13 100644
--- a/app/controllers/admin/datafields.php
+++ b/app/controllers/admin/datafields.php
@@ -94,15 +94,17 @@ class Admin_DatafieldsController extends AuthenticatedController
 
         if (Request::submitted('uebernehmen')) {
             if (Request::get('datafield_name')) {
-                $datafield->name          = Request::i18n('datafield_name');
-                if ($datafield->object_type === 'moduldeskriptor'
-                        || $datafield->object_type === 'modulteildeskriptor') {
+                $datafield->name = Request::i18n('datafield_name');
+                if (
+                    $datafield->object_type === 'moduldeskriptor'
+                    || $datafield->object_type === 'modulteildeskriptor'
+                ) {
                     $object_class = implode(',', Request::getArray('object_class'));
                     $datafield->object_class  = (trim($object_class) && $object_class != 'NULL') ? $object_class : null;
                 } elseif ($datafield->object_type === 'studycourse') {
                     $datafield->object_class  = trim(Request::option('object_class', 'all_settings'));
                 } else {
-                    $datafield->object_class  = array_sum(Request::getArray('object_class')) ?: null;
+                    $datafield->object_class  = array_sum(Request::intArray('object_class')) ?: null;
                 }
                 $datafield->edit_perms     = Request::get('edit_perms');
                 $datafield->view_perms     = Request::get('visibility_perms');
diff --git a/app/controllers/admin/domain.php b/app/controllers/admin/domain.php
index e4bb9c8..37ab11f 100644
--- a/app/controllers/admin/domain.php
+++ b/app/controllers/admin/domain.php
@@ -70,7 +70,7 @@ class Admin_DomainController extends AuthenticatedController
     {
         foreach ($args as $arg) {
             if ($arg && !preg_match('/' . UserDomain::REGEXP . '/', $arg)) {
-                throw new Trails_Exception(400);
+                throw new Trails\Exception(400);
             }
         }
 
diff --git a/app/controllers/admin/extern.php b/app/controllers/admin/extern.php
index 41833b1..732b586 100644
--- a/app/controllers/admin/extern.php
+++ b/app/controllers/admin/extern.php
@@ -66,8 +66,8 @@ class Admin_ExternController extends AuthenticatedController
         ExternPageConfig::findEachBySQL(
             function ($c) use (&$configs, &$count_not_migrated) {
                 $configs[$c->type][] = $c;
-                if (isset($c->conf['not_fixed_after_migration'])) { 
-                    $count_not_migrated++; 
+                if (isset($c->conf['not_fixed_after_migration'])) {
+                    $count_not_migrated++;
                 }
             },
             "range_id = ?", [$this->range]
@@ -165,7 +165,7 @@ class Admin_ExternController extends AuthenticatedController
                 if ($this->page->page_config->isNew()) {
                     PageLayout::postSuccess(sprintf(
                         _('Eine neue externe Seite "%$1s" vom Typ %$2s wurde angelegt.'),
-                        htmlReady($this->page->name), 
+                        htmlReady($this->page->name),
                         htmlReady($this->page->type)
                     ));
                 } else {
@@ -259,7 +259,11 @@ class Admin_ExternController extends AuthenticatedController
      */
     public function info_action(string $config_id)
     {
-        $this->page = ExternPage::get(ExternPageConfig::find($config_id));
+        $config = ExternPageConfig::find($config_id);
+        if (!$config) {
+            throw new Exception('ExternPageConfig object not found!');
+        }
+        $this->page = ExternPage::get($config);
         if ($this->page->author) {
             $this->author = '<a href="'
                 . URLHelper::getLink('dispatch.php/profile', ['username' => $this->page->author->username])
@@ -364,7 +368,7 @@ class Admin_ExternController extends AuthenticatedController
             $config->author_id = $config->editor_id = $GLOBALS['user']->id;
             $config->store();
             PageLayout::postSuccess(
-                sprintf(_('Die Konfiguration "%s" wurde erfolgreich importiert.'), 
+                sprintf(_('Die Konfiguration "%s" wurde erfolgreich importiert.'),
                 htmlReady($config->name)
             ));
         }
@@ -436,7 +440,7 @@ class Admin_ExternController extends AuthenticatedController
      */
     protected function fetchPlugins(bool $is_system): void
     {
-        $plugins = PluginEngine::getPlugins('ExternPagePlugin');
+        $plugins = PluginEngine::getPlugins(ExternPagePlugin::class);
         foreach ($plugins as $plugin) {
             if (
                 $is_system === $plugin->isSystemPage()
diff --git a/app/controllers/admin/install.php b/app/controllers/admin/install.php
index 0054445..e45c281 100644
--- a/app/controllers/admin/install.php
+++ b/app/controllers/admin/install.php
@@ -1,7 +1,7 @@
 <?php
-require_once __DIR__ . '/../studip_controller_properties_trait.php';
+require_once __DIR__ . '/../../../lib/classes/StudipControllerPropertiesTrait.php';
 
-class Admin_InstallController extends Trails_Controller
+class Admin_InstallController extends Trails\Controller
 {
     use StudipControllerPropertiesTrait;
 
diff --git a/app/controllers/admin/lockrules.php b/app/controllers/admin/lockrules.php
index 56879fe..202a2e9 100644
--- a/app/controllers/admin/lockrules.php
+++ b/app/controllers/admin/lockrules.php
@@ -164,7 +164,7 @@ class Admin_LockrulesController extends AuthenticatedController
     {
         $this->lock_rule = LockRule::find($lock_rule_id);
         if (!(!$this->lock_rule->isNew() && ($GLOBALS['perm']->have_perm('root') || $this->lock_rule->user_id === $GLOBALS['user']->id))) {
-            throw new Trails_Exception(403);
+            throw new Trails\Exception(403);
         }
         CSRFProtection::verifyUnsafeRequest();
         if ($this->lock_rule->delete()) {
@@ -186,4 +186,4 @@ class Admin_LockrulesController extends AuthenticatedController
         }
         return $this->lock_rule->store();
     }
-}
\ No newline at end of file
+}
diff --git a/app/controllers/admin/plugin.php b/app/controllers/admin/plugin.php
index 903c45e..8a6935b 100644
--- a/app/controllers/admin/plugin.php
+++ b/app/controllers/admin/plugin.php
@@ -86,7 +86,7 @@ class Admin_PluginController extends AuthenticatedController
      * update information is available, an error message is set in
      * this controller and an empty array is returned.
      *
-     * @param array     array of plugin meta data
+     * @param array $plugins array of plugin meta data
      */
     private function get_update_info($plugins)
     {
@@ -127,7 +127,6 @@ class Admin_PluginController extends AuthenticatedController
         }
 
         $plugin_manager = PluginManager::getInstance();
-        $plugin_filter = Request::option('plugin_filter', '');
 
         $plugins = $plugin_manager->getPluginInfos($this->plugin_filter);
 
@@ -200,7 +199,6 @@ class Admin_PluginController extends AuthenticatedController
                         _('Die Position von Plugin "%s" wurde verändert.'),
                         $plugin['name']
                     );
-                    $changed = true;
                 }
             }
         }
@@ -344,7 +342,7 @@ class Admin_PluginController extends AuthenticatedController
     /**
      * Ask for confirmation from the user before deleting a plugin.
      *
-     * @param integer   id of plugin to delete
+     * @param int $plugin_id id of plugin to delete
      */
     public function ask_delete_action($plugin_id)
     {
@@ -366,7 +364,7 @@ class Admin_PluginController extends AuthenticatedController
     /**
      * Completely delete a plugin from the system.
      *
-     * @param integer   id of plugin to delete
+     * @param int $plugin_id id of plugin to delete
      */
     public function delete_action($plugin_id)
     {
@@ -390,7 +388,7 @@ class Admin_PluginController extends AuthenticatedController
     /**
      * Download a ZIP file containing the given plugin.
      *
-     * @param integer   id of plugin to download
+     * @param int $plugin_id id of plugin to download
      */
     public function download_action($plugin_id)
     {
@@ -441,16 +439,16 @@ class Admin_PluginController extends AuthenticatedController
         $update_info = $this->plugin_admin->getUpdateInfo($plugins);
 
         $update = $this->flash['update'];
-        $update_status = [];
-
-        // update each plugin in turn
-        foreach ($update as $id) {
-            if (isset($update_info[$id]['update'])) {
-                try {
-                    $update_url = $update_info[$id]['update']['url'];
-                    $this->plugin_admin->installPluginFromURL($update_url);
-                } catch (PluginInstallationException $ex) {
-                    $update_errors[] = sprintf('%s: %s', $plugins[$id]['name'], $ex->getMessage());
+
+        if (!empty($update)) { // update each plugin in turn
+            foreach ($update as $id) {
+                if (isset($update_info[$id]['update'])) {
+                    try {
+                        $update_url = $update_info[$id]['update']['url'];
+                        $this->plugin_admin->installPluginFromURL($update_url);
+                    } catch (PluginInstallationException $ex) {
+                        $update_errors[] = sprintf('%s: %s', $plugins[$id]['name'], $ex->getMessage());
+                    }
                 }
             }
         }
@@ -473,6 +471,8 @@ class Admin_PluginController extends AuthenticatedController
     /**
      * Show a page describing this plugin's meta data and description,
      * if available.
+     *
+     * @param int $plugin_id if of plugin to show manifest
      */
     public function manifest_action($plugin_id)
     {
@@ -491,7 +491,7 @@ class Admin_PluginController extends AuthenticatedController
     /**
      * migrate a plugin to top version
      *
-     * @param integer   id of plugin to migrate
+     * @param int $plugin_id id of plugin to migrate
      */
     public function migrate_action($plugin_id)
     {
@@ -516,7 +516,7 @@ class Admin_PluginController extends AuthenticatedController
      * register a plugin in database when it
      * already exists in file system
      *
-     * @param integer   number of found plugin
+     * @param int $number number of found plugin
      */
     public function register_action($number)
     {
diff --git a/app/controllers/admin/sem_classes.php b/app/controllers/admin/sem_classes.php
index c0b098f..7993c4b 100644
--- a/app/controllers/admin/sem_classes.php
+++ b/app/controllers/admin/sem_classes.php
@@ -65,7 +65,7 @@ class Admin_SemClassesController extends AuthenticatedController
     {
         Navigation::activateItem("/admin/locations/sem_classes");
 
-        $plugins = PluginManager::getInstance()->getPlugins("StudipModule");
+        $plugins = PluginManager::getInstance()->getPlugins(StudipModule::class);
         $this->sem_class = SemClass::getClasses()[Request::get("id")];
         $modules = [];
         foreach ($this->sem_class->getModuleObjects() as $plugin) {
diff --git a/app/controllers/admin/tree.php b/app/controllers/admin/tree.php
index 1afc438..c8f2a8f 100644
--- a/app/controllers/admin/tree.php
+++ b/app/controllers/admin/tree.php
@@ -130,12 +130,15 @@ class Admin_TreeController extends AuthenticatedController
         $node->parent_id = Request::option('parent_id');
 
         $parent = $classname::getNode(Request::option('parent_id'));
-        $maxprio = max(array_map(
-            function ($c) {
-                return $c->priority;
-            },
-            $parent->getChildNodes()
-        ));
+        $children = $parent->getChildNodes();
+        $maxprio = !empty($children)
+            ? max(array_map(
+                function ($c) {
+                    return $c->priority;
+                },
+                $children
+            ))
+            : 0;
         $node->priority = $maxprio + 1;
 
         if (Request::option('studip_object_id')) {
diff --git a/app/controllers/admin/user.php b/app/controllers/admin/user.php
index 70dfdf1..37a5d2e 100644
--- a/app/controllers/admin/user.php
+++ b/app/controllers/admin/user.php
@@ -1440,17 +1440,13 @@ class Admin_UserController extends AuthenticatedController
         ];
         $queries[] = [
             'desc'  => _("Anzahl der Wikiseiten"),
-            'query' => "SELECT COUNT(*) FROM wiki WHERE user_id = ? GROUP BY user_id",
+            'query' => "SELECT COUNT(*) FROM `wiki_pages` WHERE `user_id` = ? GROUP BY `user_id`",
         ];
         $queries[] = [
             'desc'  => _("Anzahl der Umfragen"),
             'query' => "SELECT COUNT(*) FROM questionnaires WHERE user_id = ? GROUP BY user_id",
         ];
         $queries[] = [
-            'desc'  => _("Anzahl der Evaluationen"),
-            'query' => "SELECT COUNT(*) FROM eval WHERE author_id = ? GROUP BY author_id",
-        ];
-        $queries[] = [
             'desc'    => _("Anzahl der Dateien in Veranstaltungen und Einrichtungen"),
             'query'   => "SELECT COUNT(file_refs.id)
                   FROM (file_refs INNER JOIN files ON file_refs.file_id = files.id)
@@ -1478,7 +1474,7 @@ class Admin_UserController extends AuthenticatedController
             'details' => "files",
         ];
 
-        foreach (PluginEngine::getPlugins('ForumModule') as $plugin) {
+        foreach (PluginEngine::getPlugins(ForumModule::class) as $plugin) {
             $table     = $plugin->getEntryTableInfo();
             $queries[] = [
                 'desc'  => $plugin->getPluginName() . ' - ' . _("Anzahl der Postings"),
@@ -1723,7 +1719,7 @@ class Admin_UserController extends AuthenticatedController
         )->asDialog();
         $actions->addLink(
             _('Konten zusammenführen'),
-            $this->url_for('admin/user/migrate/' . ((!empty($this->user) && is_array($this->user)) ? $this->user['user_id'] : '')),
+            $this->url_for('admin/user/migrate/' . (!empty($this->user['user_id']) ? $this->user['user_id'] : '')),
             Icon::create('community')
         );
 
diff --git a/app/controllers/admission/courseset.php b/app/controllers/admission/courseset.php
index b39cdfb..65d4247 100644
--- a/app/controllers/admission/courseset.php
+++ b/app/controllers/admission/courseset.php
@@ -23,18 +23,17 @@ class Admission_CoursesetController extends AuthenticatedController
     {
         parent::before_filter($action, $args);
 
-        if (!Request::isXhr()) {
-            PageLayout::setTitle(_('Anmeldesets'));
-            // Get only own courses if user doesn't have permission to edit institute-wide coursesets.
-            $this->onlyOwnCourses = true;
-            if ($GLOBALS['perm']->have_perm('admin') || ($GLOBALS['perm']->have_perm('dozent') && Config::get()->ALLOW_DOZENT_COURSESET_ADMIN)) {
-                // We have access to institute-wide course sets, so all courses may be assigned.
-                $this->onlyOwnCourses = false;
-                Navigation::activateItem('/browse/coursesets/sets');
-            } else {
-                throw new AccessDeniedException();
-            }
+        PageLayout::setTitle(_('Anmeldesets'));
+        // Get only own courses if user doesn't have permission to edit institute-wide coursesets.
+        $this->onlyOwnCourses = true;
+        if ($GLOBALS['perm']->have_perm('admin') || ($GLOBALS['perm']->have_perm('dozent') && Config::get()->ALLOW_DOZENT_COURSESET_ADMIN)) {
+            // We have access to institute-wide course sets, so all courses may be assigned.
+            $this->onlyOwnCourses = false;
+            Navigation::activateItem('/browse/coursesets/sets');
+        } else {
+            throw new AccessDeniedException();
         }
+
         PageLayout::addScript('studip-admission.js');
 
         $views = new ActionsWidget();
@@ -44,6 +43,7 @@ class Admission_CoursesetController extends AuthenticatedController
             Icon::create('add')
         )->setActive($action === 'configure');
         Sidebar::Get()->addWidget($views);
+
         if (!isset($this->instant_course_set_view)) {
             $this->instant_course_set_view = false;
         }
@@ -327,15 +327,19 @@ class Admission_CoursesetController extends AuthenticatedController
      *
      * @param String $coursesetId the course set to delete
      */
-    public function delete_action($coursesetId) {
+    public function delete_action($coursesetId)
+    {
         $this->courseset = new CourseSet($coursesetId);
-        if (Request::int('really')) {
-            $this->courseset->delete();
-            $this->redirect($this->url_for('admission/courseset'));
+
+        if (!$this->courseset->isUserAllowedToEdit(User::findCurrent()->id)) {
+            throw new AccessDeniedException(_('Sie dürfen diese Anmelderegel nicht löschen.'));
         }
-        if (Request::int('cancel')) {
-            $this->redirect($this->url_for('admission/courseset'));
+
+        if (Request::bool('really')) {
+            $this->courseset->delete();
         }
+
+        $this->redirect($this->url_for('admission/courseset'));
     }
 
     /**
@@ -757,11 +761,17 @@ class Admission_CoursesetController extends AuthenticatedController
 
         $ids = Request::optionArray('ids');
         if (Request::submitted('delete')) {
+            $deleted = 0;
             foreach ($ids as $id) {
                 $courseset = new CourseSet($id);
-                $courseset->delete();
+                if ($courseset->isUserAllowedToEdit(User::findCurrent()->id)) {
+                    $courseset->delete();
+                    $deleted += 1;
+                }
+            }
+            if ($deleted > 0) {
+                PageLayout::postSuccess(_('Die Anmeldesets wurden gelöscht.'));
             }
-            PageLayout::postSuccess(_('Die Anmeldesets wurden gelöscht.'));
         }
 
         $this->redirect('admission/courseset');
diff --git a/app/controllers/api/authorizations.php b/app/controllers/api/authorizations.php
deleted file mode 100644
index 543bc79..0000000
--- a/app/controllers/api/authorizations.php
+++ /dev/null
@@ -1,58 +0,0 @@
-<?php
-
-require_once 'lib/bootstrap-api.php';
-
-/**
-* @deprecated Since Stud.IP 5.0. Will be removed in Stud.IP 6.0.
- **/
-class Api_AuthorizationsController extends AuthenticatedController
-{
-    /**
-     *
-     **/
-    public function before_filter(&$action, &$args)
-    {
-        parent::before_filter($action, $args);
-
-        $GLOBALS['perm']->check('autor');
-
-        Navigation::activateItem('/profile/settings/api');
-        PageLayout::setTitle(_('Applikationen'));
-
-        $this->types = [
-            'website' => _('Website'),
-            'program' => _('Herkömmliches Desktopprogramm'),
-            'app'     => _('Mobile App')
-        ];
-    }
-
-    /**
-     *
-     **/
-    public function index_action()
-    {
-        $this->consumers = RESTAPI\UserPermissions::get($GLOBALS['user']->id)->getConsumers();
-        $this->types = [
-            'website' => _('Website'),
-            'program' => _('Herkömmliches Desktopprogramm'),
-            'app'     => _('Mobile App')
-        ];
-
-        $widget = new SidebarWidget();
-        $widget->setTitle(_('Informationen'));
-        $widget->addElement(new WidgetElement(_('Dies sind die Apps, die Zugriff auf Ihren Account haben.')));
-        Sidebar::Get()->addWidget($widget);
-    }
-
-    /**
-     *
-     **/
-    public function revoke_action($id)
-    {
-        $consumer = new RESTAPI\Consumer\OAuth($id);
-        $consumer->revokeAccess($GLOBALS['user']->id);
-
-        PageLayout::postMessage(MessageBox::success(_('Der Applikation wurde der Zugriff auf Ihre Daten untersagt.')));
-        $this->redirect('api/authorizations');
-    }
-}
diff --git a/app/controllers/api/oauth.php b/app/controllers/api/oauth.php
deleted file mode 100644
index bc80c90..0000000
--- a/app/controllers/api/oauth.php
+++ /dev/null
@@ -1,113 +0,0 @@
-<?php
-
-require_once 'lib/bootstrap-api.php';
-
-/**
- * @deprecated Since Stud.IP 5.0. Will be removed in Stud.IP 6.0.
- **/
-class Api_OauthController extends StudipController
-{
-    /**
-     *
-     **/
-    public function before_filter(&$action, &$args)
-    {
-        parent::before_filter($action, $args);
-
-        # initialize Stud.IP-Session
-        page_open(['sess' => 'Seminar_Session',
-                        'auth' => 'Seminar_Default_Auth',
-                        'perm' => 'Seminar_Perm',
-                        'user' => 'Seminar_User']);
-
-        $this->set_layout(null);
-    }
-
-    /**
-     *
-     **/
-    public function index_action()
-    {
-        $this->render_text('TODO');
-    }
-
-    /**
-     *
-     **/
-    public function request_token_action()
-    {
-        $server = new OAuthServer();
-        $token = $server->requestToken();
-
-        $this->response->headers = [];
-        $this->render_nothing();
-    }
-
-    /**
-     *
-     **/
-    public function authorize_action()
-    {
-        global $user, $auth;
-
-        $auth_plugin = Config::get()->API_OAUTH_AUTH_PLUGIN;
-        if ($GLOBALS['user']->id === 'nobody' && $auth_plugin !== 'Standard' && !Request::option('sso')) {
-            $params = $_GET;
-            $params['sso'] = strtolower($auth_plugin);
-            $this->redirect($this->url_for('api/oauth/authorize?' . http_build_query($params)));
-            return;
-        } else {
-            $auth->login_if($user->id === 'nobody');
-        }
-
-        $user_id = RESTAPI\Consumer\OAuth::getOAuthId($GLOBALS['user']->id);
-
-        try {
-            $consumer = RESTAPI\Consumer\Base::detectConsumer('oauth', 'request');
-            if (!$consumer) {
-                $this->response->set_status(400, 'No consumer detected');
-                $this->render_nothing();
-                return;
-            }
-
-            if (Request::submitted('allow')) {
-                $result = $consumer->grantAccess($GLOBALS['user']->id);
-
-                $redirect_uri = Request::get('oauth_callback', $consumer->callback);
-
-                if ($redirect_uri) {
-                    $this->redirect($redirect_uri);
-                } else {
-                    // No oauth_callback, show the user the result of the authorization
-                    // ** your code here **
-                    PageLayout::postMessage(MessageBox::success(_('Sie haben der Applikation Zugriff auf Ihre Daten gewährt.')));
-                    $this->redirect('api/authorizations#' . $consumer->auth_key);
-                }
-                return;
-           }
-        } catch (OAuthException2 $e) {
-            // No token to be verified in the request, show a page where the user can enter the token to be verified
-            // **your code here**
-            die('invalid');
-        }
-
-        PageLayout::disableHeader();
-        PageLayout::setTitle(sprintf(_('"%s" bittet um Zugriff'), $consumer->title));
-        $this->set_layout($GLOBALS['template_factory']->open('layouts/base.php'));
-        $this->consumer = $consumer;
-        $this->token    = Request::option('oauth_token');
-        $this->oauth_callback = Request::get('oauth_callback');
-    }
-
-    /**
-     *
-     **/
-    public function access_token_action()
-    {
-        $server = new OAuthServer();
-        $server->accessToken();
-
-        $this->response->headers = [];
-        $this->render_nothing();
-    }
-}
diff --git a/app/controllers/api/oauth2/applications.php b/app/controllers/api/oauth2/applications.php
index d08ec1e..fd6a1bb 100644
--- a/app/controllers/api/oauth2/applications.php
+++ b/app/controllers/api/oauth2/applications.php
@@ -31,7 +31,7 @@ class Api_Oauth2_ApplicationsController extends AuthenticatedController
         $this->application = $this->formatApplication($accessToken);
 
         if (!$this->application) {
-            throw new Trails_Exception(500, 'Error finding client.');
+            throw new Trails\Exception(500, 'Error finding client.');
         }
     }
 
@@ -42,7 +42,7 @@ class Api_Oauth2_ApplicationsController extends AuthenticatedController
         $user = User::findCurrent();
         $accessToken = AccessToken::find(Request::option('application'));
         if (!$accessToken) {
-            throw new Trails_Exception(404);
+            throw new Trails\Exception(404);
         }
         if ($accessToken['user_id'] !== $user->id) {
             throw new AccessDeniedException();
diff --git a/app/controllers/api/oauth2/authorize.php b/app/controllers/api/oauth2/authorize.php
index 5628d49..6387937 100644
--- a/app/controllers/api/oauth2/authorize.php
+++ b/app/controllers/api/oauth2/authorize.php
@@ -13,7 +13,7 @@ class Api_Oauth2_AuthorizeController extends OAuth2Controller
         parent::before_filter($action, $args);
 
         if ('index' !== $action) {
-            throw new Trails_Exception(404);
+            throw new Trails\Exception(404);
         }
 
         $action = $this->determineAction();
@@ -55,7 +55,7 @@ class Api_Oauth2_AuthorizeController extends OAuth2Controller
         if ('nobody' === $GLOBALS['user']->id && 'Standard' !== $authPlugin && !Request::option('sso')) {
             $queryParams = $psrRequest->getQueryParams();
             $queryParams['sso'] = strtolower($authPlugin);
-            $this->redirect($this->authorizeURL($queryParams));
+            $this->redirect($this->url_for('api/oauth2/authorize', $queryParams));
 
             return;
         } else {
diff --git a/app/controllers/api/oauth2/oauth2_controller.php b/app/controllers/api/oauth2/oauth2_controller.php
index fd02ea9..6b3dacd 100644
--- a/app/controllers/api/oauth2/oauth2_controller.php
+++ b/app/controllers/api/oauth2/oauth2_controller.php
@@ -42,7 +42,7 @@ abstract class OAuth2Controller extends StudipController
             return $this->convertPsrResponse($psrResponse);
         }
 
-        return new Trails_Response($exception->getMessage(), [], 500);
+        return new Trails\Response($exception->getMessage(), [], 500);
     }
 
     protected function getAuthorizationServer(): AuthorizationServer
diff --git a/app/controllers/api/oauth2/token.php b/app/controllers/api/oauth2/token.php
index 0ae7ffb..755d6b7 100644
--- a/app/controllers/api/oauth2/token.php
+++ b/app/controllers/api/oauth2/token.php
@@ -8,11 +8,11 @@ class Api_Oauth2_TokenController extends OAuth2Controller
         parent::before_filter($action, $args);
 
         if ('index' !== $action) {
-            throw new Trails_Exception(404);
+            throw new Trails\Exception(404);
         }
 
         if (!Request::isPost()) {
-            throw new Trails_Exception(405);
+            throw new Trails\Exception(405);
         }
 
         $action = 'issue_token';
diff --git a/app/controllers/authenticated_controller.php b/app/controllers/authenticated_controller.php
deleted file mode 100644
index e051ffa..0000000
--- a/app/controllers/authenticated_controller.php
+++ /dev/null
@@ -1,32 +0,0 @@
-<?php
-/*
- * Copyright (C) 2009 - Marcus Lunzenauer <mlunzena@uos.de>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- */
-
-class AuthenticatedController extends StudipController
-{
-    protected $with_session = true;  //we do need to have a session for this controller
-    protected $allow_nobody = false; //nobody is not allowed and always gets a login-screen
-
-    public function before_filter(&$action, &$args)
-    {
-        parent::before_filter($action, $args);
-
-        // Restore request if present
-        if (isset($this->flash['request'])) {
-            foreach ($this->flash['request'] as $key => $value) {
-                Request::set($key, $value);
-            }
-        }
-    }
-
-    protected function keepRequest()
-    {
-        $this->flash['request'] = Request::getInstance()->getIterator()->getArrayCopy();
-    }
-}
diff --git a/app/controllers/avatar.php b/app/controllers/avatar.php
index c549cf0..aafbb98 100644
--- a/app/controllers/avatar.php
+++ b/app/controllers/avatar.php
@@ -62,8 +62,14 @@ class AvatarController extends AuthenticatedController
             Navigation::activateItem('/admin/institute/details');
         } else {
             Navigation::activateItem('/course/admin/avatar');
+
+            if ($GLOBALS['perm']->have_studip_perm('admin', $id)) {
+                $widget = new CourseManagementSelectWidget();
+                Sidebar::get()->addWidget($widget);
+            }
         }
 
+
         $avatar = $class::getAvatar($id);
         $this->avatar = $avatar->getURL($class::NORMAL);
         $this->customized = $avatar->is_customized();
diff --git a/app/controllers/blubber.php b/app/controllers/blubber.php
index c0490f0..aedf9b6 100644
--- a/app/controllers/blubber.php
+++ b/app/controllers/blubber.php
@@ -135,7 +135,7 @@ class BlubberController extends AuthenticatedController
                     'user_id' => $user_id,
                 ]);
             }
-            $this->redirect("blubber/index/{$blubber->getId()}");
+            $this->relocate("blubber/index/{$blubber->getId()}");
             return;
         }
 
@@ -271,13 +271,12 @@ class BlubberController extends AuthenticatedController
 
         $output = [];
         foreach ($_FILES as $file) {
-            $newfile = null; //is filled below
             $file_ref = null; //is also filled below
 
             if ($file['size']) {
                 $document['user_id'] = $GLOBALS['user']->id;
-                $document['filesize'] = $file['size'];
-
+                $success = false;
+                $url = '';
                 try {
                     $root_dir = Folder::findTopFolder($GLOBALS['user']->id);
                     $root_dir = $root_dir->getTypedFolder();
@@ -339,7 +338,6 @@ class BlubberController extends AuthenticatedController
                     }
                 } catch (Exception $e) {
                     $output['errors'][] = $e->getMessage();
-                    $success = false;
                 }
 
                 if ($success) {
@@ -373,21 +371,22 @@ class BlubberController extends AuthenticatedController
         }
         PageLayout::setTitle(_('Person hinzufügen'));
         if (Request::isPost() && Request::option('user_id')) {
-            $query = "INSERT IGNORE INTO blubber_mentions
-                      SET thread_id = :thread_id,
-                          user_id = :user_id,
-                          external_contact = 0,
-                          mkdate = UNIX_TIMESTAMP()";
-            $statement = DBManager::get()->prepare($query);
-            $statement->execute([
-                'thread_id' => $thread_id,
-                'user_id' => Request::option('user_id'),
-            ]);
-            $this->response->add_header('X-Dialog-Execute', 'STUDIP.Blubber.refreshThread');
-            $this->response->add_header('X-Dialog-Close', '1');
-            $this->render_json([
-                'thread_id' => $thread_id,
-            ]);
+            $data = [
+                'user_id'          => Request::option('user_id'),
+                'thread_id'        => $thread_id,
+                'external_contact' => 0,
+            ];
+
+            $blubber_mention = BlubberMention::findOneBySQL('user_id = ? AND thread_id = ?', [Request::option('user_id'), $thread_id]);
+
+            if ($blubber_mention) {
+                $blubber_mention->setData($data);
+            } else {
+                $blubber_mention = BlubberMention::create($data);
+            }
+            $blubber_mention->store();
+            $this->relocate('blubber/index/' . $thread_id);
+            return;
         }
     }
 
@@ -408,13 +407,9 @@ class BlubberController extends AuthenticatedController
                 CourseAvatar::getAvatar($course->getId())->createFromUpload('avatar');
             }
 
-            $query = "SELECT user_id
-                      FROM blubber_mentions
-                      WHERE thread_id = ?";
-            $statement = DBManager::get()->prepare($query);
-            $statement->execute([$this->thread->id]);
-            foreach ($statement->fetchFirst() as $user_id) {
-                CourseMember::insertCourseMember($course->getId(), $user_id, $user_id === $this->thread['user_id'] ? 'dozent' : 'tutor');
+            $blubber_mentions = BlubberMention::findBySQL('thread_id = ?', [$this->thread->id]);
+            foreach ($blubber_mentions as $blubber_mention) {
+                CourseMember::insertCourseMember($course->getId(), $blubber_mention->user_id, $blubber_mention->user_id === $this->thread['user_id'] ? 'dozent' : 'tutor');
             }
 
             $this->thread['context_type'] = 'course';
@@ -424,13 +419,13 @@ class BlubberController extends AuthenticatedController
 
             PluginManager::getInstance()->setPluginActivated(
                 PluginManager::getInstance()
-                    ->getPlugin('Blubber')
+                    ->getPlugin(Blubber::class)
                     ->getPluginId(),
                 $course->getId(),
                 true
             );
 
-            PageLayout::postSuccess(sprintf(_("Studiengruppe '%s' wurde angelegt."), htmlReady($course['name'])));
+            PageLayout::postSuccess(sprintf(_('Studiengruppe "%s" wurde angelegt.'), htmlReady($course['name'])));
             $this->redirect(URLHelper::getURL('seminar_main.php', ['auswahl' => $course->getId()]));
         }
     }
diff --git a/app/controllers/calendar/calendar.php b/app/controllers/calendar/calendar.php
index c605c01..0cb96ad 100644
--- a/app/controllers/calendar/calendar.php
+++ b/app/controllers/calendar/calendar.php
@@ -12,8 +12,12 @@ class Calendar_CalendarController extends AuthenticatedController
     }
 
 
-    protected function buildSidebar($schedule = false)
-    {
+    protected function buildSidebar(
+        bool $schedule = false,
+        string $user_id = '',
+        string $group_id = ''
+    ) {
+
         $sidebar = Sidebar::get();
 
         $actions = new ActionsWidget();
@@ -25,11 +29,17 @@ class Calendar_CalendarController extends AuthenticatedController
                 ['data-dialog' => 'size=default']
             );
         } else {
+            $params = [];
+            if ($user_id) {
+                $params['user_id'] = $user_id;
+            } elseif ($group_id) {
+                $params['group_id'] = $group_id;
+            }
             $actions->addLink(
                 _('Termin anlegen'),
-                $this->url_for('calendar/date/add'),
+                $this->url_for('calendar/date/add', $params),
                 Icon::create('add'),
-                ['data-dialog' => 'size=auto']
+                ['data-dialog' => 'size=auto', 'class' => 'calendar-action']
             );
         }
 
@@ -101,6 +111,8 @@ class Calendar_CalendarController extends AuthenticatedController
     {
         PageLayout::setTitle(_('Kalender'));
 
+        $default_date = \Studip\Calendar\Helper::getDefaultCalendarDate();
+
         if (Request::isPost()) {
             //In case the checkbox of the options widget is clicked, the resulting
             //POST request must be catched here and result in a redirect.
@@ -181,7 +193,11 @@ class Calendar_CalendarController extends AuthenticatedController
             throw new AccessDeniedException(_('Sie dürfen diesen Kalender nicht sehen!'));
         }
 
-        $this->buildSidebar(false);
+        $this->buildSidebar(
+            false,
+            $calendar_owner ? $calendar_owner->id : '',
+            $selected_group ? $selected_group->id : ''
+        );
 
         $sidebar = Sidebar::get();
 
@@ -189,6 +205,7 @@ class Calendar_CalendarController extends AuthenticatedController
             if ($calendar_owner && $calendar_owner->id === User::findCurrent()->id) {
                 //The user is viewing their own calendar.
                 $options = new OptionsWidget();
+                $options->addLayoutCSSClass('calendar-action');
                 $options->addCheckbox(
                     _('Abgelehnte Termine anzeigen'),
                     Request::bool('show_declined'),
@@ -223,6 +240,7 @@ class Calendar_CalendarController extends AuthenticatedController
                         $this->url_for('calendar/calendar/index', ['view' => 'group']),
                         'group_id'
                     );
+                    $group_select->addLayoutCSSClass('calendar-action');
                     $options = [
                         '' => _('(bitte wählen)')
                     ];
@@ -249,6 +267,7 @@ class Calendar_CalendarController extends AuthenticatedController
                     $this->url_for('calendar/calendar'),
                     'user_id'
                 );
+                $calendar_select->addLayoutCSSClass('calendar-action');
                 $select_options = [
                     '' => _('(bitte wählen)'),
                     User::findCurrent()->id => _('Eigener Kalender')
@@ -321,7 +340,6 @@ class Calendar_CalendarController extends AuthenticatedController
         $slot_durations = $this->getUserCalendarSlotSettings();
 
         //Create the fullcalendar object:
-        $default_date = \Studip\Calendar\Helper::getDefaultCalendarDate();
 
         $data_url_params = [];
         if (Request::bool('show_declined')) {
@@ -432,7 +450,7 @@ class Calendar_CalendarController extends AuthenticatedController
             _('Termin anlegen'),
             $this->url_for('calendar/date/add/course_' . $course->id),
             Icon::create('add'),
-            ['data-dialog' => 'size=default']
+            ['data-dialog' => 'size=default', 'class' => 'calendar-action']
         );
         $actions->addLink(
             _('Drucken'),
@@ -564,20 +582,18 @@ class Calendar_CalendarController extends AuthenticatedController
             $course_dates = CalendarCourseDate::getEvents($begin, $end, $owner->id);
             foreach ($course_dates as $course_date) {
                 $event = $course_date->toEventData(User::findCurrent()->id);
-                $event->background_colour = '#ffffff';
+                $event->background_colour = '';
                 $event->text_colour = '#000000';
-                $event->border_colour = '#000000';
-                $event->event_classes = [];
+                $event->border_colour = '';
                 $result[] = $event->toFullcalendarEvent();
             }
             //Include relevant cancelled course dates:
             $cancelled_course_dates = CalendarCourseExDate::getEvents($begin, $end, $owner->id);
             foreach ($cancelled_course_dates as $cancelled_course_date) {
                 $event = $cancelled_course_date->toEventData(User::findCurrent()->id);
-                $event->background_colour = '#ffffff';
+                $event->background_colour = '';
                 $event->text_colour = '#000000';
-                $event->border_colour = '#000000';
-                $event->event_classes = [];
+                $event->border_colour = '';
                 $result[] = $event->toFullcalendarEvent();
             }
         }
@@ -660,7 +676,7 @@ class Calendar_CalendarController extends AuthenticatedController
     public function add_courses_action()
     {
         $selected_semester_pseudo_id = Request::option('semester_id');
-        $this->selected_semesters_id = '';
+        $this->selected_semester_id = '';
         $this->available_semester_data = [];
         $semesters = Semester::getAll();
         foreach ($semesters as $semester) {
@@ -691,8 +707,9 @@ class Calendar_CalendarController extends AuthenticatedController
             $this->selected_semester_id = $semester->id;
         } else {
             $this->selected_semester_id = $selected_semester_pseudo_id ?? '';
-            if (!Semester::exists($this->selected_semesters_id)) {
-                $this->selected_semester_id = '';
+            if (!Semester::exists($this->selected_semester_id)) {
+                $semester = Semester::findCurrent();
+                $this->selected_semester_id = $semester->id;
             }
         }
 
@@ -755,29 +772,41 @@ class Calendar_CalendarController extends AuthenticatedController
                 PageLayout::postError(_('Bitte wählen Sie aus, welche Termine exportiert werden sollen!'));
                 return;
             }
-            $ical = '';
-            $calendar_export = new ICalendarExport();
-            if ($this->dates_to_export === 'user') {
-                $ical = $calendar_export->exportCalendarDates(User::findCurrent()->id, $this->begin, $this->end);
-            } elseif ($this->dates_to_export === 'course') {
-                $ical = $calendar_export->exportCourseDates(User::findCurrent()->id, $this->begin, $this->end);
-                $ical .= $calendar_export->exportCourseExDates(User::findCurrent()->id, $this->begin, $this->end);
-            } elseif ($this->dates_to_export === 'all') {
-                $ical = $calendar_export->exportCalendarDates(User::findCurrent()->id, $this->begin, $this->end);
-                $ical .= $calendar_export->exportCourseDates(User::findCurrent()->id, $this->begin, $this->end);
-                $ical .= $calendar_export->exportCourseExDates(User::findCurrent()->id, $this->begin, $this->end);
-            }
-            $ical = $calendar_export->writeHeader() . $ical . $calendar_export->writeFooter();
-            $this->response->add_header('Content-Type', 'text/calendar;charset=utf-8');
-            $this->response->add_header('Content-Disposition', 'attachment; filename="studip.ics"');
-            $this->response->add_header('Content-Transfer-Encoding', 'binary');
-            $this->response->add_header('Pragma', 'public');
-            $this->response->add_header('Cache-Control', 'private');
-            $this->response->add_header('Content-Length', strlen($ical));
-            $this->render_text($ical);
+            $this->relocate($this->url_for('calendar/calendar/export_file', [
+                'begin' => $this->begin->format('d.m.Y'),
+                'end' => $this->end->format('d.m.Y'),
+                'dates_to_export' => $this->dates_to_export
+            ]));
         }
     }
 
+    public function export_file_action()
+    {
+        $begin = Request::getDateTime('begin', 'd.m.Y');
+        $end = Request::getDateTime('end', 'd.m.Y');
+        $dates_to_export = Request::option('dates_to_export', 'user');
+        $ical = '';
+        $calendar_export = new ICalendarExport();
+        if ($dates_to_export === 'user') {
+            $ical = $calendar_export->exportCalendarDates(User::findCurrent()->id, $begin, $end);
+        } elseif ($dates_to_export === 'course') {
+            $ical = $calendar_export->exportCourseDates(User::findCurrent()->id, $begin, $end);
+            $ical .= $calendar_export->exportCourseExDates(User::findCurrent()->id, $begin, $end);
+        } elseif ($dates_to_export === 'all') {
+            $ical = $calendar_export->exportCalendarDates(User::findCurrent()->id, $begin, $end);
+            $ical .= $calendar_export->exportCourseDates(User::findCurrent()->id, $begin, $end);
+            $ical .= $calendar_export->exportCourseExDates(User::findCurrent()->id, $begin, $end);
+        }
+        $ical = $calendar_export->writeHeader() . $ical . $calendar_export->writeFooter();
+        $this->response->add_header('Content-Type', 'text/calendar;charset=utf-8');
+        $this->response->add_header('Content-Disposition', 'attachment; filename="studip.ics"');
+        $this->response->add_header('Content-Transfer-Encoding', 'binary');
+        $this->response->add_header('Pragma', 'public');
+        $this->response->add_header('Cache-Control', 'private');
+        $this->response->add_header('Content-Length', strlen($ical));
+        $this->render_text($ical);
+    }
+
     public function import_action() {}
 
     public function import_file_action()
diff --git a/app/controllers/calendar/contentbox.php b/app/controllers/calendar/contentbox.php
index 8ba5215..b684905 100644
--- a/app/controllers/calendar/contentbox.php
+++ b/app/controllers/calendar/contentbox.php
@@ -78,21 +78,29 @@ class Calendar_ContentboxController extends StudipController
         if ($this->admin) {
             $this->isProfile = $this->single && $this->userRange;
         }
+
+        // Sort dates
+        usort($this->termine, function ($a, $b) {
+            [$a_begin, $a_end] = $this->parseBeginAndEndFromDate($a);
+            [$b_begin, $b_end] = $this->parseBeginAndEndFromDate($b);
+
+            return $a_begin - $b_begin
+                ?: $a_end - $b_end;
+        });
     }
 
     private function parseSeminar($id)
     {
-        $course = Course::find($id);
-        $this->termine = $course->getDatesWithExdates()->findBy('end_time', [$this->start, $this->start + $this->timespan], '><');
-        foreach ($this->termine as $course_date) {
-            if ($this->course_range) {
-                //Display only date and time:
-                $this->titles[$course_date->id] = $course_date->getFullName('include-room');
-            } else {
-                //Include the course title:
-                $this->titles[$course_date->id] = $course_date->getFullName('verbose');
-            }
-        }
+        // Display only date and time if in course range, include course title
+        // otherwise
+        $date_format = $this->course_range ? 'include-room' : 'verbose';
+
+        $this->termine = Course::find($id)->getDatesWithExdates()
+            ->findBy('end_time', [$this->start, $this->start + $this->timespan], '><')
+            ->map(function ($course_date) use ($date_format) {
+                $this->titles[$course_date->id] = $course_date->getFullName($date_format);
+                return $course_date;
+            });
     }
 
     private function parseUser($id)
@@ -170,4 +178,23 @@ class Calendar_ContentboxController extends StudipController
             $this->termine[] = $assignment;
         }
     }
+
+    private function parseBeginAndEndFromDate($date): array
+    {
+        if ($date instanceof CalendarDateAssignment) {
+            return [
+                $date->calendar_date->begin,
+                $date->calendar_date->end,
+            ];
+        }
+
+        if ($date instanceof CourseDate || $date instanceof CourseExDate) {
+            return [
+                $date->date,
+                $date->end_time,
+            ];
+        }
+
+        throw new Exception('Invalid date type passed: ' . get_class($date));
+    }
 }
diff --git a/app/controllers/calendar/date.php b/app/controllers/calendar/date.php
index 72f3a40..cb61a7e 100644
--- a/app/controllers/calendar/date.php
+++ b/app/controllers/calendar/date.php
@@ -27,9 +27,8 @@ class Calendar_DateController extends AuthenticatedController
             $range_id = $range_and_id[1];
         }
         if (!$range) {
-            //Show the personal calendar of the current user:
+            $range_id = Request::option('user_id', $GLOBALS['user']->id);
             $range = 'user';
-            $range_id = $GLOBALS['user']->id;
         }
 
         $owner = null;
@@ -233,6 +232,14 @@ class Calendar_DateController extends AuthenticatedController
             $this->date->repetition_end = $this->date->end;
         } else {
             $time = new DateTime();
+            if (Request::submitted('timestamp')) {
+                $time->setTimestamp(Request::int('timestamp'));
+            } elseif (Request::submitted('defaultDate')) {
+                $date_parts = explode('-', Request::get('defaultDate'));
+                if (count($date_parts) === 3) {
+                    $time->setDate($date_parts[0], $date_parts[1], $date_parts[2]);
+                }
+            }
             $time = $time->add(new DateInterval('PT1H'));
             $time->setTime(intval($time->format('H')), 0, 0);
             $this->date->begin = $time->getTimestamp();
@@ -325,15 +332,12 @@ class Calendar_DateController extends AuthenticatedController
 
         if ($this->date->isNew()) {
             if (!($owner instanceof Course)) {
-                //Assign the date to the calendar of the current user by default:
-                $user = User::findCurrent();
-                if ($user) {
-                    $this->calendar_assignment_items[] = [
-                        'value'     => $user->id,
-                        'name'      => $user->getFullName(),
-                        'deletable' => true
-                    ];
-                }
+                //Assign the date to the calendar of the owner by default:
+                $this->calendar_assignment_items[] = [
+                    'value'     => $owner->id,
+                    'name'      => $owner->getFullName(),
+                    'deletable' => true
+                ];
             }
         } else {
             $exceptions = CalendarDateException::findBySql(
diff --git a/app/controllers/calendar/schedule.php b/app/controllers/calendar/schedule.php
index 88c4304..5d9a26e 100644
--- a/app/controllers/calendar/schedule.php
+++ b/app/controllers/calendar/schedule.php
@@ -143,7 +143,7 @@ class Calendar_ScheduleController extends AuthenticatedController
             'entry_height' => $this->calendar_view->getHeight()
         ];
 
-        $factory = new Flexi_TemplateFactory($this->dispatcher->trails_root . '/views');
+        $factory = new Flexi\Factory($this->dispatcher->trails_root . '/views');
         PageLayout::addStyle($factory->render('calendar/schedule/stylesheet', $style_parameters), 'screen, print');
 
         if (Request::option('printview')) {
diff --git a/app/controllers/captcha.php b/app/controllers/captcha.php
new file mode 100644
index 0000000..37bac47
--- /dev/null
+++ b/app/controllers/captcha.php
@@ -0,0 +1,12 @@
+<?php
+final class CaptchaController extends StudipController
+{
+    public function challenge_action(): void
+    {
+        $this->response->add_header(
+            'Expires',
+            gmdate('D, d M Y H:i:s', time() + CaptchaChallenge::CHALLENGE_EXPIRATION) . ' GMT'
+        );
+        $this->render_json(CaptchaChallenge::createNewChallenge());
+    }
+}
diff --git a/app/controllers/consultation/admin.php b/app/controllers/consultation/admin.php
index bc63a1a..8ee7575 100644
--- a/app/controllers/consultation/admin.php
+++ b/app/controllers/consultation/admin.php
@@ -138,6 +138,7 @@ class Consultation_AdminController extends ConsultationController
 
         $this->room = '';
         $this->responsible = false;
+        $this->slot_count_threshold = self::SLOT_COUNT_THRESHOLD;
 
         // TODO: inst_default?
         if ($this->range instanceof User) {
@@ -155,6 +156,8 @@ class Consultation_AdminController extends ConsultationController
             $block->range = $this->range;
             $this->responsible = $block->getPossibleResponsibilites();
         }
+
+        $this->response->add_header('X-No-Buttons', '');
     }
 
     public function store_action()
@@ -186,7 +189,7 @@ class Consultation_AdminController extends ConsultationController
                 $end,
                 Request::int('day-of-week'),
                 Request::int('interval'),
-                Request::int('duration'),
+                $duration,
                 $pause_time,
                 $pause_duration
             );
@@ -214,6 +217,7 @@ class Consultation_AdminController extends ConsultationController
                 $block->note              = Request::get('note');
                 $block->size              = Request::int('size', 1);
                 $block->lock_time         = Request::int('lock_time');
+                $block->consecutive       = Request::bool('consecutive', false);
 
                 $slots = $block->createSlots(Request::int('duration'), $pause_time, $pause_duration);
                 if (count($slots) === 0) {
@@ -403,6 +407,7 @@ class Consultation_AdminController extends ConsultationController
         $this->block->mail_to_tutors = Request::bool('mail-to-tutors', false);
         $this->block->confirmation_text = trim(Request::get('confirmation-text'));
         $this->block->lock_time = Request::int('lock_time');
+        $this->block->consecutive = Request::bool('consecutive', false);
 
         foreach ($this->block->slots as $slot) {
             $slot->note = '';
@@ -535,7 +540,7 @@ class Consultation_AdminController extends ConsultationController
     public function toggle_action($what, $state, $expired = false)
     {
         if ($what === 'messages') {
-            // TODO: Applicable     everywhere?
+            // TODO: Applicable everywhere?
             $this->getUserConfig()->store(
                 'CONSULTATION_SEND_MESSAGES',
                 (bool) $state
@@ -808,7 +813,7 @@ class Consultation_AdminController extends ConsultationController
             _('Terminblöcke anlegen'),
             $this->createURL(),
             Icon::create('add')
-        )->asDialog('size=auto');
+        )->asDialog('size=big');
         $actions->addLink(
             _('Namen des Reiters ändern'),
             $this->tabURL($action === 'expired'),
diff --git a/app/controllers/consultation/consultation_controller.php b/app/controllers/consultation/consultation_controller.php
index d6927af..00e10ad 100644
--- a/app/controllers/consultation/consultation_controller.php
+++ b/app/controllers/consultation/consultation_controller.php
@@ -19,7 +19,7 @@ abstract class ConsultationController extends AuthenticatedController
             $this->range = Context::get();
             $type = 'object';
         } else {
-            $this->range = $GLOBALS['user']->getAuthenticatedUser();
+            $this->range = User::findCurrent();
         }
 
         if (!$this->range) {
@@ -60,7 +60,7 @@ abstract class ConsultationController extends AuthenticatedController
         $this->render_template('consultation/not_found', $this->layout);
     }
 
-    protected function activateNavigation($path)
+    protected function activateNavigation($path): void
     {
         $path = ltrim($path, '/');
 
@@ -73,7 +73,7 @@ abstract class ConsultationController extends AuthenticatedController
         }
     }
 
-    protected function getConsultationTitle()
+    protected function getConsultationTitle(): string
     {
         return $this->range->getConfiguration()->CONSULTATION_TAB_TITLE;
     }
@@ -103,7 +103,8 @@ abstract class ConsultationController extends AuthenticatedController
         return $block;
     }
 
-    protected function loadSlot($block_id, $slot_id)
+
+    protected function loadSlot($block_id, $slot_id): ConsultationSlot
     {
         $block = $this->loadBlock($block_id);
         $slot  = $block->slots->find($slot_id);
@@ -115,7 +116,7 @@ abstract class ConsultationController extends AuthenticatedController
         return $slot;
     }
 
-    protected function loadBooking($block_id, $slot_id, $booking_id)
+    protected function loadBooking($block_id, $slot_id, $booking_id): ConsultationBooking
     {
         $slot    = $this->loadSlot($block_id, $slot_id);
         $booking = $slot->bookings->find($booking_id);
diff --git a/app/controllers/consultation/overview.php b/app/controllers/consultation/overview.php
index ce6cd31..2afb710 100644
--- a/app/controllers/consultation/overview.php
+++ b/app/controllers/consultation/overview.php
@@ -71,6 +71,8 @@ class Consultation_OverviewController extends ConsultationController
 
             if ($this->slot->isOccupied()) {
                 PageLayout::postError(_('Dieser Termin ist bereits belegt.'));
+            } elseif (!$this->slot->isBookable()) {
+                PageLayout::postError(_('Dieser Termin ist für Buchungen gesperrt.'));
             } else {
                 $booking = new ConsultationBooking();
                 $booking->slot_id = $this->slot->id;
diff --git a/app/controllers/contact.php b/app/controllers/contact.php
index 7dd2b05..2148777 100644
--- a/app/controllers/contact.php
+++ b/app/controllers/contact.php
@@ -189,9 +189,21 @@ class ContactController extends AuthenticatedController
             $user = User::findManyByUsername(Request::getArray('user'));
         }
         if ($group) {
-            $user = User::findMany(Statusgruppen::find($group)->members->pluck('user_id'));
+            $group_object = Statusgruppen::find($group);
+            if (!$group_object) {
+                $this->set_status(404);
+                $this->render_nothing();
+                return;
+            }
+            $user = User::findMany($group_object->members->pluck('user_id'));
         }
         if (!$user) {
+            $user_object = User::findCurrent();
+            if (!$user_object) {
+                $this->set_status(404);
+                $this->render_nothing();
+                return;
+            }
             $user = User::findCurrent()->contacts;
         }
 
diff --git a/app/controllers/contents/courseware.php b/app/controllers/contents/courseware.php
index f0d5023..d4291df 100644
--- a/app/controllers/contents/courseware.php
+++ b/app/controllers/contents/courseware.php
@@ -262,7 +262,7 @@ class Contents_CoursewareController extends CoursewareController
      */
     private function isCoursewareEnabled($course_id): bool
     {
-        $studip_module = PluginManager::getInstance()->getPlugin('CoursewareModule');
+        $studip_module = PluginManager::getInstance()->getPlugin(CoursewareModule::class);
 
         if (!$studip_module || !$studip_module->isActivated($course_id)) {
             return false;
@@ -311,7 +311,7 @@ class Contents_CoursewareController extends CoursewareController
         );
 
         if (!$struct) {
-            throw new Trails_Exception(404, _('Der geteilte Inhalt kann nicht gefunden werden.'));
+            throw new Trails\Exception(404, _('Der geteilte Inhalt kann nicht gefunden werden.'));
         }
 
         if (!$struct->canRead($user) && !$struct->canEdit($user)) {
diff --git a/app/controllers/course/admission.php b/app/controllers/course/admission.php
index 56342bb..14a9b20 100644
--- a/app/controllers/course/admission.php
+++ b/app/controllers/course/admission.php
@@ -31,7 +31,7 @@ class Course_AdmissionController extends AuthenticatedController
         if (!get_object_type($this->course_id, ['sem']) ||
             SeminarCategories::GetBySeminarId($this->course_id)->studygroup_mode ||
             !$GLOBALS['perm']->have_studip_perm('tutor', $this->course_id)) {
-            throw new Trails_Exception(403);
+            throw new Trails\Exception(403);
         }
 
         $this->course = Course::find($this->course_id);
@@ -488,7 +488,7 @@ class Course_AdmissionController extends AuthenticatedController
             }
             $this->course_set_name = $course_set->getName();
         } else {
-            throw new Trails_Exception(400);
+            throw new Trails\Exception(400);
         }
     }
 
@@ -503,7 +503,7 @@ class Course_AdmissionController extends AuthenticatedController
                 $this->redirect($response->headers['Location']);
             }
         } else {
-            throw new Trails_Exception(403);
+            throw new Trails\Exception(403);
         }
     }
 
@@ -518,7 +518,7 @@ class Course_AdmissionController extends AuthenticatedController
                 $this->redirect($response->headers['Location']);
             }
         } else {
-            throw new Trails_Exception(403);
+            throw new Trails\Exception(403);
         }
     }
 
diff --git a/app/controllers/course/basicdata.php b/app/controllers/course/basicdata.php
index 8cc7d94..97ec053 100644
--- a/app/controllers/course/basicdata.php
+++ b/app/controllers/course/basicdata.php
@@ -445,6 +445,14 @@ class Course_BasicdataController extends AuthenticatedController
             $widget = new CourseManagementSelectWidget();
             $sidebar->addWidget($widget);
         }
+
+        foreach ($this->flash['msg'] ?? [] as $msg) {
+            match ($msg[0]) {
+                'msg'   => PageLayout::postSuccess($msg[1]),
+                'error' => PageLayout::postError($msg[1]),
+                'info'  => PageLayout::postInfo($msg[1]),
+            };
+        }
     }
 
     /**
@@ -956,20 +964,30 @@ class Course_BasicdataController extends AuthenticatedController
     private function _getTypes($sem, $data, &$changable = true)
     {
         $sem_types = [];
+
+        $sem_classes = [];
         if ($GLOBALS['perm']->have_perm("admin")) {
             foreach (SemClass::getClasses() as $sc) {
                 if (!$sc['course_creation_forbidden']) {
-                    $sem_types[$sc['name']] = array_map(function ($st) {
-                        return $st['name'];
-                    }, $sc->getSemTypes());
+                    $sem_classes[] = $sc;
                 }
             }
         } else {
-            $sc = $sem->getSemClass();
+            $sem_classes[] = $sem->getSemClass();
+        }
+
+        if (!$sem->isStudyGroup()) {
+            $sem_classes = array_filter($sem_classes, function (SemClass $sc) {
+                return !$sc['studygroup_mode'];
+            });
+        }
+
+        foreach ($sem_classes as $sc) {
             $sem_types[$sc['name']] = array_map(function ($st) {
                 return $st['name'];
             }, $sc->getSemTypes());
         }
+
         if (!in_array($data['status'], array_flatten(array_values(array_map('array_keys', $sem_types))))) {
             $class_name = $sem->getSemClass()->offsetGet('name');
             if (!isset($sem_types[$class_name])) {
diff --git a/app/controllers/course/block_appointments.php b/app/controllers/course/block_appointments.php
index fef0d31..ad28b1e 100644
--- a/app/controllers/course/block_appointments.php
+++ b/app/controllers/course/block_appointments.php
@@ -33,7 +33,7 @@ class Course_BlockAppointmentsController extends AuthenticatedController
             SeminarCategories::GetBySeminarId($this->course_id)->studygroup_mode ||
             !$GLOBALS['perm']->have_studip_perm("tutor", $this->course_id)
         ) {
-            throw new Trails_Exception(400);
+            throw new Trails\Exception(400);
         }
         PageLayout::setHelpKeyword('Basis.VeranstaltungenVerwaltenAendernVonZeitenUndTerminen');
         PageLayout::setTitle(Course::findCurrent()->getFullName() . " - " . _('Blockveranstaltungstermine anlegen'));
diff --git a/app/controllers/course/cancel_dates.php b/app/controllers/course/cancel_dates.php
index 0d5463c..8da0d09 100644
--- a/app/controllers/course/cancel_dates.php
+++ b/app/controllers/course/cancel_dates.php
@@ -39,7 +39,7 @@ class Course_CancelDatesController extends AuthenticatedController
             $this->course_id = $this->dates[0]->range_id;
         }
         if (!get_object_type($this->course_id, ['sem']) || !$perm->have_studip_perm("tutor", $this->course_id)) {
-            throw new Trails_Exception(400);
+            throw new Trails\Exception(400);
         }
         PageLayout::setHelpKeyword('Basis.VeranstaltungenVerwaltenAendernVonZeitenUndTerminen');
         PageLayout::setTitle(Course::findCurrent()->getFullName() . " - " . _('Veranstaltungstermine absagen'));
diff --git a/app/controllers/course/change_view.php b/app/controllers/course/change_view.php
index 156a68a..63395b6 100644
--- a/app/controllers/course/change_view.php
+++ b/app/controllers/course/change_view.php
@@ -16,7 +16,6 @@
  */
 class Course_ChangeViewController extends AuthenticatedController
 {
-    // see Trails_Controller#before_filter
     public function before_filter(&$action, &$args)
     {
         parent::before_filter($action, $args);
@@ -28,7 +27,7 @@ class Course_ChangeViewController extends AuthenticatedController
      * Sets the current course into participant view.
      * Only available for tutor upwards.
      *
-     * @throws Trails_Exception Someone with unfitting rights tried to call here.
+     * @throws Trails\Exception Someone with unfitting rights tried to call here.
      */
     public function set_changed_view_action()
     {
@@ -43,7 +42,7 @@ class Course_ChangeViewController extends AuthenticatedController
      * Resets a course currently in participant view to normal view
      * with real rights.
      *
-     * @throws Trails_Exception Someone with unfitting rights tried to call here.
+     * @throws Trails\Exception Someone with unfitting rights tried to call here.
      */
     public function reset_changed_view_action()
     {
diff --git a/app/controllers/course/contentmodules.php b/app/controllers/course/contentmodules.php
index 923c61b..d37d1bb 100644
--- a/app/controllers/course/contentmodules.php
+++ b/app/controllers/course/contentmodules.php
@@ -261,14 +261,19 @@ class Course_ContentmodulesController extends AuthenticatedController
             }
         }
 
-        PageLayout::setTitle(sprintf(_('Informationen über %s'), $this->metadata['displayname']));
+        $this->metadata['icon'] = $this->getIconFromMetadata($this->metadata, $this->plugin);
+
+        PageLayout::setTitle(sprintf(
+            _('Informationen über %s'),
+            $this->metadata['displayname'] ?? $this->plugin->getPluginName()
+        ));
     }
 
     private function getModules(Range $context)
     {
         $list = [];
 
-        foreach (PluginEngine::getPlugins('StudipModule') as $plugin) {
+        foreach (PluginEngine::getPlugins(StudipModule::class) as $plugin) {
             if (!$plugin->isActivatableForContext($context)) {
                 continue;
             }
@@ -291,6 +296,7 @@ class Course_ContentmodulesController extends AuthenticatedController
             $visibility = $tool ? $tool->getVisibilityPermission() : 'nobody';
 
             $metadata = $plugin->getMetadata();
+            $icon = $this->getIconFromMetadata($metadata, $plugin);
             $list[$plugin_id] = [
                 'id'             => $plugin_id,
                 'moduleclass'    => get_class($plugin),
@@ -299,7 +305,7 @@ class Course_ContentmodulesController extends AuthenticatedController
                 'displayname'    => $displayname,
                 'visibility'     => $visibility,
                 'active'         => (bool) $tool,
-                'icon'           => $this->getIconFromMetadata($metadata, $plugin),
+                'icon'           => $icon ? $icon->asImagePath() : null,
                 'summary'        => $metadata['summary'] ?? null,
                 'mandatory'      => $this->sem_class->isModuleMandatory(get_class($plugin)),
                 'highlighted'    => (bool) $plugin->isHighlighted(),
@@ -315,7 +321,7 @@ class Course_ContentmodulesController extends AuthenticatedController
      * @param array $metadata
      * @param CorePlugin|StudIPPlugin $plugin
      */
-    private function getIconFromMetadata(array $metadata, $plugin): ?string
+    private function getIconFromMetadata(array $metadata, $plugin): ?Icon
     {
         $icon = $metadata['icon_clickable'] ?? $metadata['icon'] ?? null;
 
@@ -332,7 +338,7 @@ class Course_ContentmodulesController extends AuthenticatedController
             $icon = Icon::create($plugin->getPluginURL() . '/' . $icon);
         }
 
-        return $icon->copyWithRole(Icon::ROLE_CLICKABLE)->asImagePath();
+        return $icon->copyWithRole(Icon::ROLE_CLICKABLE);
     }
 
     private function getCoreIcon(string $path): ?Icon
diff --git a/app/controllers/course/courseware.php b/app/controllers/course/courseware.php
index 22b124b..f0b873a 100644
--- a/app/controllers/course/courseware.php
+++ b/app/controllers/course/courseware.php
@@ -52,22 +52,20 @@ class Course_CoursewareController extends CoursewareController
 
     public function courseware_action($unit_id = null):  void
     {
-        global $user;
-
         Navigation::activateItem('course/courseware/unit');
         if ($this->unitsNotFound) {
             PageLayout::postMessage(MessageBox::info(_('Es wurde kein Lernmaterial gefunden.')));
             return;
         }
+        $user = User::findCurrent();
         $this->setCoursewareSidebar();
 
-        $this->user_id = $user->id;
         /** @var array<mixed> $last */
-        $last = UserConfig::get($this->user_id)->getValue('COURSEWARE_LAST_ELEMENT');
+        $last = UserConfig::get($user->id)->getValue('COURSEWARE_LAST_ELEMENT');
         $lastStructuralElement = \Courseware\StructuralElement::findOneById($last);
 
         if ($unit_id === null) {
-            if (isset($lastStructuralElement) && $lastStructuralElement->canVisit(User::findCurrent())) {
+            if (isset($lastStructuralElement) && $lastStructuralElement->canVisit($user)) {
                 $this->redirectToFirstUnit('course', Context::getId(), $last);
             } else {
                 $this->redirectToFirstUnit('course', Context::getId(), []);
diff --git a/app/controllers/course/dates.php b/app/controllers/course/dates.php
index a4e18e9..f64d66b 100644
--- a/app/controllers/course/dates.php
+++ b/app/controllers/course/dates.php
@@ -80,7 +80,10 @@ class Course_DatesController extends AuthenticatedController
             )->asDialog();
         }
 
-        if (Seminar::setInstance(new Seminar(Course::findCurrent()))->getSlotModule('documents') && CourseDateFolder::availableInRange(Course::findCurrent(), User::findCurrent()->id)) {
+        if (
+            Seminar::setInstance(new Seminar(Course::findCurrent()))->getSlotModule('documents')
+            && CourseDateFolder::availableInRange(Course::findCurrent(), User::findCurrent() ? User::findCurrent()->id : null)
+        ) {
             $actions->addLink(
                 _('Sitzungsordner anlegen'),
                 $this->url_for('course/dates/create_folders'),
diff --git a/app/controllers/course/details.php b/app/controllers/course/details.php
index 2a330e3..e1c9493 100644
--- a/app/controllers/course/details.php
+++ b/app/controllers/course/details.php
@@ -32,7 +32,7 @@ class Course_DetailsController extends AuthenticatedController
 
         $this->course = Course::find($course_id);
         if (!$this->course) {
-            throw new Trails_Exception(
+            throw new Trails\Exception(
                 404,
                 _('Es konnte keine Veranstaltung gefunden werden')
             );
diff --git a/app/controllers/course/enrolment.php b/app/controllers/course/enrolment.php
index eb4428e..420b5ca 100644
--- a/app/controllers/course/enrolment.php
+++ b/app/controllers/course/enrolment.php
@@ -37,7 +37,7 @@ class Course_EnrolmentController extends AuthenticatedController
             return false;
         }
         if (!get_object_type($this->course_id, ['sem'])) {
-            throw new Trails_Exception(400);
+            throw new Trails\Exception(400);
         }
         $course = Seminar::GetInstance($this->course_id);
         $enrolment_info = $course->getEnrolmentInfo($GLOBALS['user']->id);
diff --git a/app/controllers/course/forum/forum_controller.php b/app/controllers/course/forum/forum_controller.php
index 71d1aa0..65eec63 100644
--- a/app/controllers/course/forum/forum_controller.php
+++ b/app/controllers/course/forum/forum_controller.php
@@ -23,7 +23,7 @@ abstract class ForumController extends StudipController {
 
         parent::before_filter($action, $args);
 
-        $this->flash = Trails_Flash::instance();
+        $this->flash = Trails\Flash::instance();
 
         // Set help keyword for Stud.IP's user-documentation and page title
         PageLayout::setHelpKeyword('Basis.Forum');
diff --git a/app/controllers/course/gradebook/lecturers.php b/app/controllers/course/gradebook/lecturers.php
index b3b1f82..7ab02e7 100644
--- a/app/controllers/course/gradebook/lecturers.php
+++ b/app/controllers/course/gradebook/lecturers.php
@@ -258,7 +258,7 @@ class Course_Gradebook_LecturersController extends AuthenticatedController
     public function edit_custom_definition_action($definitionId)
     {
         if (!$this->definition = Definition::findOneBySQL('id = ? AND course_id = ?', [$definitionId, \Context::getId()])) {
-            throw new \Trails_Exception(404);
+            throw new \Trails\Exception(404);
         }
 
         // show template
@@ -271,7 +271,7 @@ class Course_Gradebook_LecturersController extends AuthenticatedController
     {
         CSRFProtection::verifyUnsafeRequest();
         if (!$definition = Definition::findOneBySQL('id = ? AND course_id = ?', [$definitionId, \Context::getId()])) {
-            throw new \Trails_Exception(404);
+            throw new \Trails\Exception(404);
         }
 
         $name = trim(\Request::get('name', ''));
diff --git a/app/controllers/course/grouping.php b/app/controllers/course/grouping.php
index 4f35b53..3cef673 100644
--- a/app/controllers/course/grouping.php
+++ b/app/controllers/course/grouping.php
@@ -36,6 +36,11 @@ class Course_GroupingController extends AuthenticatedController
         if (!$GLOBALS['perm']->have_studip_perm('tutor', $this->course->id)) {
             throw new AccessDeniedException(_('Sie haben leider nicht die notwendige Berechtigung für diese Aktion.'));
         }
+
+        if ($GLOBALS['perm']->have_studip_perm('admin', $this->course->id)) {
+            $widget = new CourseManagementSelectWidget();
+            Sidebar::get()->addWidget($widget);
+        }
     }
 
     /**
diff --git a/app/controllers/course/lti.php b/app/controllers/course/lti.php
index e0ca2cf..4db7776 100644
--- a/app/controllers/course/lti.php
+++ b/app/controllers/course/lti.php
@@ -1,4 +1,7 @@
 <?php
+
+use Studip\OAuth2\NegotiatesWithPsr7;
+
 /**
  * course/lti.php - LTI consumer API for Stud.IP
  *
@@ -13,6 +16,8 @@
 
 class Course_LtiController extends StudipController
 {
+    use NegotiatesWithPsr7;
+
     /**
      * Callback function being called before an action is executed.
      */
@@ -268,22 +273,15 @@ class Course_LtiController extends StudipController
      */
     public function save_link_action($tool_id)
     {
-        require_once 'vendor/oauth-php/library/OAuthRequestVerifier.php';
-
         $tool = LtiTool::find($tool_id);
         $lti_msg = Request::get('lti_msg');
         $lti_errormsg = Request::get('lti_errormsg');
         $content_items = Request::get('content_items');
         $content_items = json_decode($content_items, true);
 
-        OAuthStore::instance('PDO', [
-            'dsn' => 'mysql:host=' . $GLOBALS['DB_STUDIP_HOST'] . ';dbname=' . $GLOBALS['DB_STUDIP_DATABASE'],
-            'username' => $GLOBALS['DB_STUDIP_USER'],
-            'password' => $GLOBALS['DB_STUDIP_PASSWORD']
-        ]);
-
-        $oarv = new OAuthRequestVerifier();
-        $oarv->verifySignature($tool->consumer_secret, false, false);
+        if (!Studip\OAuth1::verifyRequest($this->getPsrRequest(), $tool->consumer_secret, '')) {
+            throw new Exception('Could not verify request.');
+        }
 
         if (is_array($content_items) && count($content_items['@graph'])) {
             // we only support selecting a single content item
@@ -452,18 +450,11 @@ class Course_LtiController extends StudipController
      */
     public function outcome_action($id)
     {
-        require_once 'vendor/oauth-php/library/OAuthRequestVerifier.php';
-
         $lti_data = LtiData::find($id);
 
-        OAuthStore::instance('PDO', [
-            'dsn' => 'mysql:host=' . $GLOBALS['DB_STUDIP_HOST'] . ';dbname=' . $GLOBALS['DB_STUDIP_DATABASE'],
-            'username' => $GLOBALS['DB_STUDIP_USER'],
-            'password' => $GLOBALS['DB_STUDIP_PASSWORD']
-        ]);
-
-        $oarv = new OAuthRequestVerifier();
-        $oarv->verifySignature($lti_data->getConsumerSecret(), false, false);
+        if (!Studip\OAuth1::verifyRequest($this->getPsrRequest(), $lti_data->getConsumerSecret(), '')) {
+            throw new Exception('Could not verify request.');
+        }
 
         // fetch and parse POST data
         $message = file_get_contents('php://input');
diff --git a/app/controllers/course/lvgselector.php b/app/controllers/course/lvgselector.php
index 3542a11..c8223a9 100644
--- a/app/controllers/course/lvgselector.php
+++ b/app/controllers/course/lvgselector.php
@@ -17,15 +17,13 @@ require 'config/mvv_config.php';
 
 class Course_LvgselectorController extends AuthenticatedController
 {
-
-    // see Trails_Controller#before_filter
     public function before_filter(&$action, &$args)
     {
         parent::before_filter($action, $args);
 
         $this->course = Course::findCurrent();
         if (!$this->course) {
-            throw new Trails_Exception(404, _('Es wurde keine Veranstaltung ausgewählt!'));
+            throw new Trails\Exception(404, _('Es wurde keine Veranstaltung ausgewählt!'));
         }
         $this->course_id = $this->course->id;
         if (!$GLOBALS['perm']->have_studip_perm('tutor', $this->course_id)) {
@@ -37,6 +35,11 @@ class Course_LvgselectorController extends AuthenticatedController
         $widget = new HelpbarWidget();
         $widget->addElement(new WidgetElement(_('Auf dieser Seite kann die Veranstaltung ausgewählten Lehrveranstaltungsgruppen zugeordnet werden.')));
         Helpbar::get()->addWidget($widget);
+
+        if ($GLOBALS['perm']->have_studip_perm('admin', $this->course_id)) {
+            $widget = new CourseManagementSelectWidget();
+            Sidebar::get()->addWidget($widget);
+        }
     }
 
     /**
diff --git a/app/controllers/course/members.php b/app/controllers/course/members.php
index 3eae083..1ec1587 100644
--- a/app/controllers/course/members.php
+++ b/app/controllers/course/members.php
@@ -232,7 +232,7 @@ class Course_MembersController extends AuthenticatedController
             $course_member = AdmissionApplication::find([$user_id, $this->course_id]);
         }
         if (is_null($course_member)) {
-            throw new Trails_Exception(400);
+            throw new Trails\Exception(400);
         }
         $this->comment = $course_member->comment;
         $this->user = User::find($user_id);
@@ -265,7 +265,7 @@ class Course_MembersController extends AuthenticatedController
             $course_member = AdmissionApplication::find([$user_id, $this->course_id]);
         }
         if (!Request::submitted('save') || is_null($course_member)) {
-            throw new Trails_Exception(400);
+            throw new Trails\Exception(400);
         }
         $course_member->comment = Request::get('comment');
 
diff --git a/app/controllers/course/messenger.php b/app/controllers/course/messenger.php
index 3e692aa..710ac87 100644
--- a/app/controllers/course/messenger.php
+++ b/app/controllers/course/messenger.php
@@ -12,16 +12,20 @@ class Course_MessengerController extends AuthenticatedController
 
     public function course_action($thread_id = null)
     {
-        if (Context::get()) {
-            PageLayout::setTitle(Context::get()->getFullName() . ' - ' . _('Blubber'));
+        $context = Context::get();
+
+        if (!$context) {
+            throw new CheckObjectException(_('Sie haben kein Objekt gewählt.'));
         }
 
         if (Navigation::hasItem('/course/blubber')) {
             Navigation::activateItem('/course/blubber');
         }
 
+        PageLayout::setTitle($context->getFullName() . ' - ' . _('Blubber'));
+
         $this->search = '';
-        $this->threads = BlubberThread::findByContext(Context::get()->id, true, Context::getType());
+        $this->threads = BlubberThread::findByContext($context->id, true, Context::getType());
         $this->thread = null;
         $this->threads_more_down = 0;
 
diff --git a/app/controllers/course/overview.php b/app/controllers/course/overview.php
index 96e7f5a..876de5a 100644
--- a/app/controllers/course/overview.php
+++ b/app/controllers/course/overview.php
@@ -58,8 +58,6 @@ class Course_OverviewController extends AuthenticatedController
 
         // Fetch  votes
         if (Config::get()->VOTE_ENABLE) {
-            $response             = $this->relay('evaluation/display/' . $this->course_id);
-            $this->evaluations    = $response->body;
             $response             = $this->relay('questionnaire/widget/' . $this->course_id);
             $this->questionnaires = $response->body;
         }
@@ -113,7 +111,7 @@ class Course_OverviewController extends AuthenticatedController
             $this->avatar   = StudygroupAvatar::getAvatar($this->course_id);
         }
 
-        $this->plugins = PluginEngine::getPlugins('StandardPlugin', $this->course_id);
+        $this->plugins = PluginEngine::getPlugins(StandardPlugin::class, $this->course_id);
 
         $sidebar = Sidebar::get();
 
diff --git a/app/controllers/course/room_requests.php b/app/controllers/course/room_requests.php
index ab802b7..b091047 100644
--- a/app/controllers/course/room_requests.php
+++ b/app/controllers/course/room_requests.php
@@ -46,7 +46,7 @@ class Course_RoomRequestsController extends AuthenticatedController
             SeminarCategories::GetBySeminarId($this->course_id)->studygroup_mode ||
             !$GLOBALS['perm']->have_studip_perm("tutor", $this->course_id)
         ) {
-            throw new Trails_Exception(400);
+            throw new Trails\Exception(400);
         }
 
         PageLayout::setHelpKeyword('Basis.VeranstaltungenVerwaltenAendernVonZeitenUndTerminen');
@@ -143,25 +143,15 @@ class Course_RoomRequestsController extends AuthenticatedController
         // a single date or whole course
         $this->request_range_id = Request::get('range_id', Context::getId());
 
-        if (!isset($_SESSION[$this->request_id])) {
-            $_SESSION[$this->request_id] = [];
-        }
+        $this->init_session();
         $_SESSION[$this->request_id]['range'] = $this->request_range ?: $_SESSION[$this->request_id]['range'] ?? null;
         $_SESSION[$this->request_id]['range_ids'] = $this->request_range_ids ?: [$this->request_range_id];
-        $_SESSION[$this->request_id]['search_by'] = '';
-        $_SESSION[$this->request_id]['room_category_id'] = '';
-        $_SESSION[$this->request_id]['room_id'] = '';
-        $_SESSION[$this->request_id]['room_name'] = '';
-        $_SESSION[$this->request_id]['selected_properties'] = [];
-
-        $this->request = null;
 
         // look for existing request or create a new one
         $this->request = new RoomRequest($this->request_id);
         // time ranges (start date, end date)
         $this->request->setRangeFields($_SESSION[$this->request_id]['range'], $_SESSION[$this->request_id]['range_ids']);
         $this->request_time_intervals = $this->request->getTimeIntervals();
-
     }
 
     /**
@@ -211,7 +201,6 @@ class Course_RoomRequestsController extends AuthenticatedController
                 );
             }
         }
-
     }
 
     /**
@@ -227,7 +216,6 @@ class Course_RoomRequestsController extends AuthenticatedController
                 _('Das Erstellen von Raumanfragen ist nicht erlaubt!')
             );
         }
-
         $this->request_id = $request_id;
         $this->step = (int)$step;
         $this->room_name = $_SESSION[$request_id]['room_name'];
@@ -266,15 +254,17 @@ class Course_RoomRequestsController extends AuthenticatedController
         $this->selected_room = Resource::find($_SESSION[$request_id]['room_id'] ?: $this->request->resource_id);
 
         $this->selected_room_category_id = $this->selected_room->category_id ?? $_SESSION[$request_id]['room_category_id'] ?? null;
+        $this->category = $this->selected_room_category_id ? ResourceCategory::find($this->selected_room_category_id) : null;
 
         $_SESSION[$request_id]['room_category_id'] = $_SESSION[$request_id]['room_category_id'] ?? $this->selected_room->category_id ?? null;
 
         // after selecting a room, go to next step or stay here if no room was selected at all
         if (Request::submitted('select_room')) {
             $this->selected_room_id = Request::get('selected_room_id');
+            $room = Room::find($this->selected_room_id);
             $_SESSION[$request_id]['room_id'] = $this->selected_room_id;
+            $_SESSION[$request_id]['room_category_id'] = $room->category_id;
             $_SESSION[$request_id]['select_room'] = true;
-
             $this->redirect(
                 'course/room_requests/request_check_properties/' . $this->request_id
             );
@@ -289,8 +279,6 @@ class Course_RoomRequestsController extends AuthenticatedController
             );
             return;
         }
-
-        // or we filter via category
         else if (Request::get('category_id') && Request::submitted('select_properties')) {
             $_SESSION[$request_id]['search_by'] = 'category';
             $_SESSION[$request_id]['room_category_id'] = Request::get('category_id');
@@ -299,74 +287,35 @@ class Course_RoomRequestsController extends AuthenticatedController
             );
             return;
         } else if (Request::submitted('reset_category')) {
-            //Delete all selected properties from the session since the category is reset
-            $_SESSION[$request_id]['selected_properties'] = [];
-            $_SESSION[$request_id]['room_category_id'] = '';
-            $_SESSION[$request_id]['room_name'] = '';
-            $_SESSION[$request_id]['room_id'] = '';
-            $this->redirect('course/room_requests/request_find_available_properties/' . $this->request_id . '/1');
+            $this->init_session();
+            $this->redirect('course/room_requests/new_request');
             return;
         }
 
         // for step 2: after choosing a specific room OR searching via properties
         if ($this->step === 2) {
-            if ($_SESSION[$request_id]['search_by'] == 'roomname') {
-                // find category via room
-                $this->category = ResourceCategory::find($this->selected_room_category_id);
-                if ($this->category) {
-                    $this->available_properties = $this->category->getRequestableProperties();
-                }
-
-                $this->selected_properties = $_SESSION[$request_id]['selected_properties'];
-                $this->room = Room::find($_SESSION[$request_id]['room_id']);
-                $this->selected_properties['seats'] = $_SESSION[$request_id]['selected_properties']['seats']
-                    ?: $this->course->admission_turnout
-                    ?: Config::get()->RESOURCES_ROOM_REQUEST_DEFAULT_SEATS;
-                $_SESSION[$request_id]['selected_properties']['seats'] = $this->selected_properties['seats'];
-            } else if ($_SESSION[$request_id]['search_by'] === 'category') {
+            if (!empty(Request::getArray('selected_properties'))) {
+                $this->selected_properties = Request::getArray('selected_properties');
+            } else {
+                $this->selected_properties =  $_SESSION[$request_id]['selected_properties'];
+            }
+            $_SESSION[$request_id]['selected_properties'] = $this->selected_properties;
+            if ($_SESSION[$request_id]['search_by'] === 'roomname') {
+                $this->selected_properties = $_SESSION[$request_id]['selected_properties'] ?? null;
                 $this->room = Room::find($_SESSION[$request_id]['room_id']);
-                if ($this->room) {
-                    $this->grouped_properties = $this->room->getGroupedProperties();
-                    foreach ($this->grouped_properties as $properties) {
-                        foreach ($properties as $property) {
-                            $this->selected_properties[$property->name] = $property->state;
-                        }
-                    }
+                if (!isset($_SESSION[$request_id]['selected_properties']['seats'])) {
+                    $this->selected_properties['seats'] = $this->course->admission_turnout ?? Config::get()->RESOURCES_ROOM_REQUEST_DEFAULT_SEATS;
                 }
-
+                $_SESSION[$request_id]['selected_properties']['seats'] = $this->selected_properties['seats'];
+                $_SESSION[$request_id]['room_category_id'] = $this->selected_room_category_id;
+            } else {
+                // let's find all the properties belonging to the selected category
+                $this->room_category_id = $_SESSION[$request_id]['room_category_id'];
             }
 
-            // find rooms fitting to category and properties
-            if (Request::submitted('search_rooms')) {
-                $this->selected_properties = Request::getArray('selected_properties');
-                $_SESSION[$request_id]['selected_properties'] = $this->selected_properties;
-                // no min number of seats
-                if (
-                    (!$_SESSION[$request_id]['selected_properties']['seats'] || $_SESSION[$request_id]['selected_properties']['seats'] < 1)
-                    && $_SESSION[$request_id]['search_by'] === 'category'
-                ) {
-                    PageLayout::postError(
-                        _('Die Mindestanzahl der Sitzplätze beträgt 1!')
-                    );
-                    $this->redirect(
-                        'course/room_requests/request_find_matching_rooms/' . $request_id . '/' . $this->step
-                    );
-                    return;
-                } else {
-                    $this->redirect(
-                        'course/room_requests/request_find_matching_rooms/' . $request_id . '/' . $this->step
-                    );
-                    return;
-                }
+            if ($this->category) {
+                $this->available_properties = $this->category->getRequestableProperties();
             }
-
-            // let's find all the properties belonging to the selected category
-            $this->room_category_id = $_SESSION[$request_id]['room_category_id'];
-            $this->category = ResourceCategory::find($this->room_category_id);
-            $this->available_properties = $this->category->getRequestableProperties();
-
-            // properties, like 'Sitzplätze', 'behindertengerecht' etc
-            $this->selected_properties = $_SESSION[$request_id]['selected_properties'] ?? null;
             $this->preparation_time = $_SESSION[$request_id]['preparation_time'] ?? null;
             $this->comment = $_SESSION[$request_id]['comment'] ?? null;
             $this->request->category_id = $_SESSION[$request_id]['room_category_id'];
@@ -375,7 +324,10 @@ class Course_RoomRequestsController extends AuthenticatedController
             if (Request::submitted('show_summary')) {
                 $this->selected_room_id = Request::get('selected_room_id');
                 $_SESSION[$request_id]['room_id'] = $this->selected_room_id;
-                $_SESSION[$request_id]['selected_properties'] = Request::getArray('selected_properties');
+                $room = Room::find($this->selected_room_id);
+                if ($room) {
+                    $_SESSION[$request_id]['room_category_id'] = $room->category_id;
+                }
                 $this->redirect('course/room_requests/request_show_summary/' . $this->request_id );
             }
         }
@@ -394,16 +346,18 @@ class Course_RoomRequestsController extends AuthenticatedController
                 _('Das Erstellen von Raumanfragen ist nicht erlaubt!')
             );
         }
-
         $this->request_id = $request_id;
         $this->step = (int)$step;
 
         $this->request = new RoomRequest($this->request_id);
-        $this->request->setRangeFields($_SESSION[$this->request_id]['range'], $_SESSION[$this->request_id]['range_ids']);
+        $this->request->setRangeFields(
+            $_SESSION[$this->request_id]['range'] ?? null,
+            $_SESSION[$this->request_id]['range_ids'] ?? null
+        );
 
         // let's find all the properties belonging to the selected category
         $this->room_category_id = $_SESSION[$request_id]['room_category_id'] ?: $this->request->category_id;
-        $this->room_name = $_SESSION[$request_id]['room_name'];
+        $this->room_name = $_SESSION[$request_id]['room_name'] ?? '';
         $this->selected_room = Resource::find($_SESSION[$request_id]['room_id'] ?: $this->request->resource_id);
         $this->category = $this->room_category_id ? ResourceCategory::find($this->room_category_id) : '';
         $this->available_properties = $this->room_category_id ? $this->category->getRequestableProperties() : '';
@@ -418,7 +372,10 @@ class Course_RoomRequestsController extends AuthenticatedController
         $this->comment = $_SESSION[$request_id]['comment'] ?? null;
 
         // when searching for a room name, list found room
-        if ($_SESSION[$request_id]['room_name'] !== '') {
+        if (
+            isset($_SESSION[$request_id]['room_name'])
+            && $_SESSION[$request_id]['room_name'] !== ''
+        ) {
             $search_properties['room_category_id'] = $this->room_category_id;
             $search_properties['seats'] = [
                 1,
@@ -455,11 +412,13 @@ class Course_RoomRequestsController extends AuthenticatedController
         }
 
         $this->request_id = $request_id;
-
+        $this->selected_properties = Request::getArray('selected_properties');
         // select a room, search for a room name or search for rooms matching properties
         if (Request::submitted('select_room')) {
             $this->selected_room_id = Request::get('selected_room_id');
+            $room = Room::find($this->selected_room_id);
             $_SESSION[$request_id]['room_id'] = $this->selected_room_id;
+            $_SESSION[$request_id]['room_category_id'] = $room->category_id;
             $_SESSION[$request_id]['select_room'] = true;
             $this->step = 2;
             $this->request = new RoomRequest($this->request_id);
@@ -467,7 +426,6 @@ class Course_RoomRequestsController extends AuthenticatedController
                 'course/room_requests/request_find_matching_rooms/' . $this->request_id . '/' . $this->step
             );
         } else if (Request::get('room_name') && Request::submitted('search_by_name')) {
-            $this->selected_properties = Request::getArray('selected_properties');
             $this->category_id = Request::get('category_id');
             $_SESSION[$request_id]['selected_properties'] = $this->selected_properties;
             $_SESSION[$request_id]['room_category_id'] = $this->category_id;
@@ -479,7 +437,6 @@ class Course_RoomRequestsController extends AuthenticatedController
             );
 
         } else if (Request::submitted('search_rooms')) {
-            $this->selected_properties = Request::getArray('selected_properties');
             $this->category_id = Request::get('category_id');
             $_SESSION[$request_id]['room_category_id'] = $this->category_id;
             $_SESSION[$request_id]['selected_properties'] = $this->selected_properties;
@@ -506,8 +463,7 @@ class Course_RoomRequestsController extends AuthenticatedController
             }
         } else if (Request::submitted('reset_category')) {
             //Delete all selected properties from the session since the category is reset
-            $_SESSION[$request_id]['selected_properties'] = [];
-            $_SESSION[$request_id]['room_category_id'] = '';
+            $this->init_session();
             $this->redirect('course/room_requests/request_find_available_properties/' . $this->request_id . '/1');
         } else if (Request::submitted('search_by_category')) {
             if (Request::get('category_id') === '0') {
@@ -521,12 +477,11 @@ class Course_RoomRequestsController extends AuthenticatedController
             );
         } else if (Request::submitted('show_summary')) {
             $this->request = new RoomRequest($this->request_id);
-            $this->selected_properties = Request::getArray('selected_properties');
-
-            $_SESSION[$request_id]['selected_properties'] = $this->selected_properties;
             $this->selected_room_id = Request::get('selected_room_id');
+            $room = Room::find($this->selected_room_id);
             $_SESSION[$request_id]['room_id'] = $this->selected_room_id;
-
+            $_SESSION[$request_id]['room_category_id'] = $room->category_id ?? $_SESSION[$request_id]['room_category_id'];
+            $_SESSION[$request_id]['selected_properties'] = $this->selected_properties;
             $this->redirect('course/room_requests/request_show_summary/' . $this->request_id  );
         } else {
             $room = Room::find($_SESSION[$request_id]['room_id']);
@@ -569,7 +524,6 @@ class Course_RoomRequestsController extends AuthenticatedController
         );
 
         $this->selected_room_category = ResourceCategory::find($_SESSION[$request_id]['room_category_id'] ?? $this->request->category_id);
-
         $this->selected_room = Resource::find($_SESSION[$request_id]['room_id'] ?? $this->request->resource_id);
 
         $this->room_id = $_SESSION[$request_id]['room_id'] ?? $this->request->resource_id;
@@ -592,7 +546,7 @@ class Course_RoomRequestsController extends AuthenticatedController
 
         $_SESSION[$request_id]['search_by'] = $this->selected_room ? 'roomname' : 'category';
         $_SESSION[$request_id]['room_category_id'] = $this->selected_room_category->id;
-        $_SESSION[$request_id]['room_id'] = $this->selected_room->id;
+        $_SESSION[$request_id]['room_id'] = $this->selected_room ? $this->selected_room->id : '';
     }
 
     public function store_request_action($request_id)
@@ -629,8 +583,12 @@ class Course_RoomRequestsController extends AuthenticatedController
             $this->request->store();
 
             //Store the properties:
-            foreach ($_SESSION[$request_id]['selected_properties'] as $name => $state) {
-                $this->request->setProperty($name, $state);
+            if (isset($_SESSION[$request_id]['selected_properties'])) {
+                foreach ($_SESSION[$request_id]['selected_properties'] as $name => $state) {
+                    if (!empty($state)) {
+                        $this->request->setProperty($name, $state);
+                    }
+                }
             }
 
             // once stored, we can delete the session data for this request
@@ -707,7 +665,7 @@ class Course_RoomRequestsController extends AuthenticatedController
     {
         $request = RoomRequest::find($request_id);
         if (!$request) {
-            throw new Trails_Exception(403);
+            throw new Trails\Exception(403);
         }
         if (Request::isGet()) {
             PageLayout::postQuestion(sprintf(
@@ -723,4 +681,19 @@ class Course_RoomRequestsController extends AuthenticatedController
         }
         $this->redirect('course/timesrooms/index');
     }
+
+    private function init_session()
+    {
+        $_SESSION[$this->request_id] = array_merge(
+            $_SESSION[$this->request_id] ?? [],
+            [
+                'search_by'           => '',
+                'room_category_id'    => '',
+                'room_id'             => '',
+                'room_name'           => '',
+                'select_room'         => false,
+                'selected_properties' => [],
+            ]
+        );
+    }
 }
diff --git a/app/controllers/course/scm.php b/app/controllers/course/scm.php
index 66af981..4c5d4eb 100644
--- a/app/controllers/course/scm.php
+++ b/app/controllers/course/scm.php
@@ -93,7 +93,7 @@ class Course_ScmController extends AuthenticatedController
         $this->scm  = $id ? $this->scms->find($id) : $this->scms->first();
 
         if (!$this->scm && $this->scms->count() > 0) {
-            throw new Trails_Exception(404, _('Es konnte keine freie Informationsseite mit der angegebenen Id gefunden werden.'));
+            throw new Trails\Exception(404, _('Es konnte keine freie Informationsseite mit der angegebenen Id gefunden werden.'));
         }
 
         if (Request::get('verify') === 'delete') {
diff --git a/app/controllers/course/statusgroups.php b/app/controllers/course/statusgroups.php
index c15733d..6f96299 100644
--- a/app/controllers/course/statusgroups.php
+++ b/app/controllers/course/statusgroups.php
@@ -762,7 +762,7 @@ class Course_StatusgroupsController extends AuthenticatedController
 
             // Safety check if no group_id at all.
             if (!$group_id) {
-                throw new Trails_Exception(400);
+                throw new Trails\Exception(400);
             }
         }
 
@@ -1487,4 +1487,20 @@ class Course_StatusgroupsController extends AuthenticatedController
         return $members->orderBy($order);
 
     }
+
+    public function details_action(Statusgruppen $group): void
+    {
+        $course = Course::findCurrent();
+
+        if ($course->id !== $group->range_id) {
+            throw new AccessDeniedException();
+        }
+
+        PageLayout::setTitle(sprintf(
+            _('Personen der Gruppe %s'),
+            $group->name
+        ));
+
+        $this->group = $group;
+    }
 }
diff --git a/app/controllers/course/study_areas.php b/app/controllers/course/study_areas.php
index df54bb4..e951d11 100644
--- a/app/controllers/course/study_areas.php
+++ b/app/controllers/course/study_areas.php
@@ -18,7 +18,6 @@ require_once 'lib/webservices/api/studip_lecture_tree.php';
 
 class Course_StudyAreasController extends AuthenticatedController
 {
-    // see Trails_Controller#before_filter
     public function before_filter(&$action, &$args)
     {
         parent::before_filter($action, $args);
@@ -101,7 +100,7 @@ class Course_StudyAreasController extends AuthenticatedController
     public function save_action()
     {
         if($this->locked) {
-            throw new Trails_Exception(403);
+            throw new Trails\Exception(403);
         }
 
         $params = [];
diff --git a/app/controllers/course/studygroup.php b/app/controllers/course/studygroup.php
index b75d91e..cd08ba3 100644
--- a/app/controllers/course/studygroup.php
+++ b/app/controllers/course/studygroup.php
@@ -10,8 +10,6 @@ require_once 'lib/user_visible.inc.php';
  */
 class Course_StudygroupController extends AuthenticatedController
 {
-
-    // see Trails_Controller#before_filter
     public function before_filter(&$action, &$args)
     {
         parent::before_filter($action, $args);
@@ -596,6 +594,11 @@ class Course_StudygroupController extends AuthenticatedController
         global $perm;
 
         $id = Context::getId();
+
+        if (!$id) {
+            throw new CheckObjectException(_('Sie haben kein Objekt gewählt.'));
+        }
+
         $user = Request::username('user');
 
         if ($from_status === 'moderator') {
@@ -780,7 +783,7 @@ class Course_StudygroupController extends AuthenticatedController
             // send invite message to user
             $msg     = new messaging();
             $sem     = new Seminar($id);
-            $message = sprintf(_("%s möchte Sie auf die Studiengruppe %s aufmerksam machen. Klicken Sie auf den untenstehenden Link, um direkt zur Studiengruppe zu gelangen.\n\n %s"),
+            $message = sprintf(_("%s möchte Sie auf die Studiengruppe %s aufmerksam machen. Klicken Sie auf den folgenden Link, um direkt zur Studiengruppe zu gelangen.\n\n %s"),
                 get_fullname(), $sem->name, URLHelper::getlink("dispatch.php/course/studygroup/details/" . $id, ['cid' => null]));
             $subject = _("Sie wurden in eine Studiengruppe eingeladen");
             $msg->insert_message($message, get_username($receiver), '', '', '', '', '', $subject);
@@ -846,7 +849,7 @@ class Course_StudygroupController extends AuthenticatedController
                 return;
             }
         }
-        throw new Trails_Exception(401);
+        throw new Trails\Exception(401);
     }
 
 
diff --git a/app/controllers/course/timesrooms.php b/app/controllers/course/timesrooms.php
index 2e3b3fe..4788eee 100644
--- a/app/controllers/course/timesrooms.php
+++ b/app/controllers/course/timesrooms.php
@@ -14,7 +14,7 @@ class Course_TimesroomsController extends AuthenticatedController
      * @param String $action Action to be executed
      * @param Array  $args Arguments passed to the action
      *
-     * @throws Trails_Exception when either no course was found or the user
+     * @throws Trails\Exception when either no course was found or the user
      *                          may not access this area
      */
     public function before_filter(&$action, &$args)
@@ -23,7 +23,7 @@ class Course_TimesroomsController extends AuthenticatedController
 
         // Try to find a valid course
         if (!Course::findCurrent()) {
-            throw new Trails_Exception(404, _('Es wurde keine Veranstaltung ausgewählt!'));
+            throw new Trails\Exception(404, _('Es wurde keine Veranstaltung ausgewählt!'));
         }
 
         if (!$GLOBALS['perm']->have_studip_perm('tutor', Course::findCurrent()->id)) {
@@ -250,7 +250,7 @@ class Course_TimesroomsController extends AuthenticatedController
     /**
      * Edit the start-semester of a course
      *
-     * @throws Trails_DoubleRenderError
+     * @throws Trails\Exceptions\DoubleRenderError
      */
     public function editSemester_action()
     {
@@ -331,11 +331,6 @@ class Course_TimesroomsController extends AuthenticatedController
         $this->date       = CourseDate::find($termin_id) ?: CourseExDate::find($termin_id);
         $this->attributes = [];
 
-        if ($request = RoomRequest::findByDate($this->date->id)) {
-            $this->params = ['request_id' => $request->getId()];
-        } else {
-            $this->params = ['new_room_request_type' => 'date_' . $this->date->id];
-        }
         $this->only_bookable_rooms = Request::submitted('only_bookable_rooms');
 
         if (Config::get()->RESOURCES_ENABLE) {
@@ -373,7 +368,7 @@ class Course_TimesroomsController extends AuthenticatedController
      *
      * @param $termin_id
      *
-     * @throws Trails_DoubleRenderError
+     * @throws Trails\Exceptions\DoubleRenderError
      */
     public function saveDate_action($termin_id)
     {
@@ -439,7 +434,7 @@ class Course_TimesroomsController extends AuthenticatedController
         }
 
         // Set assigned groups
-        $assigned_groups       = Request::optionArray('assigned_groups');
+        $assigned_groups       = Request::optionArray('assigned-groups');
         $termin->statusgruppen = Statusgruppen::findMany($assigned_groups);
 
         $termin->store();
@@ -449,7 +444,11 @@ class Course_TimesroomsController extends AuthenticatedController
         }
 
         // Set Room
-        $old_room_id = $termin->room_booking->resource_id;
+        if ($termin->room_booking) {
+            $old_room_id = $termin->room_booking->resource_id;
+        } else {
+            $old_room_id = null;
+        }
         $singledate = new SingleDate($termin);
         if ($singledate->setTime($date, $end_time)) {
             $singledate->store();
@@ -517,7 +516,7 @@ class Course_TimesroomsController extends AuthenticatedController
                 '<strong>' . htmlReady($singledate->toString()) . '</strong>'
             ));
         }
-        if ($singledate->messages['error']) {
+        if (!empty($singledate->messages['error'])) {
             PageLayout::postError(
                 _('Die folgenden Fehler traten beim Bearbeiten des Termins auf:'),
                 htmlReady($singledate->messages['error'])
@@ -549,7 +548,7 @@ class Course_TimesroomsController extends AuthenticatedController
     /**
      * Save Single Date
      *
-     * @throws Trails_DoubleRenderError
+     * @throws Trails\Exceptions\DoubleRenderError
      */
     public function saveSingleDate_action()
     {
@@ -1490,23 +1489,10 @@ class Course_TimesroomsController extends AuthenticatedController
         }
         Sidebar::Get()->addWidget($widget);
 
-        if ($GLOBALS['perm']->have_perm('admin')) {
-            $list = new SelectWidget(
-                _('Veranstaltungen'),
-                $this->indexURL(),
-                'cid'
-            );
 
-            foreach (AdminCourseFilter::get()->getCoursesForAdminWidget() as $seminar) {
-                $list->addElement(new SelectElement(
-                    $seminar['Seminar_id'],
-                    $seminar['Name'],
-                    $seminar['Seminar_id'] === Context::getId(),
-                    $seminar['VeranstaltungsNummer'] . ' ' . $seminar['Name']
-                ));
-            }
-            $list->size = 8;
-            Sidebar::Get()->addWidget($list);
+        if ($GLOBALS['perm']->have_studip_perm('admin', $this->course->id)) {
+            $widget = new CourseManagementSelectWidget();
+            Sidebar::get()->addWidget($widget);
         }
     }
 
@@ -1701,7 +1687,7 @@ class Course_TimesroomsController extends AuthenticatedController
             } else {
                 $user_rooms = RoomManager::getUserRooms($current_user);
                 foreach ($user_rooms as $room) {
-                    if ($room->userHasBookingRights($current_user, $begin, $end)) {
+                    if ($room->userHasBookingRights($current_user, $begin ?? null, $end ?? null)) {
                         $rooms_with_booking_permissions++;
                         if ($only_bookable_rooms) {
                             foreach ($all_time_intervals as $interval) {
diff --git a/app/controllers/course/wiki.php b/app/controllers/course/wiki.php
index 7a3a09e..4de56a7 100644
--- a/app/controllers/course/wiki.php
+++ b/app/controllers/course/wiki.php
@@ -18,7 +18,7 @@ class Course_WikiController extends AuthenticatedController
         parent::before_filter($action, $args);
         object_set_visit_module('wiki');
         $this->range = Context::get();
-        $this->plugin = PluginManager::getInstance()->getPlugin('CoreWiki');
+        $this->plugin = PluginManager::getInstance()->getPlugin(CoreWiki::class);
 
         PageLayout::setTitle(Navigation::getItem('/course/wiki')->getTitle());
     }
@@ -117,8 +117,9 @@ class Course_WikiController extends AuthenticatedController
         $startPage = WikiPage::find($this->range->getConfiguration()->WIKI_STARTPAGE_ID);
         $this->contentbar = ContentBar::get()
             ->setTOC(CoreWiki::getTOC($this->page))
-            ->setIcon(Icon::create('wiki'))
-            ->setInfo(sprintf(
+            ->setIcon(Icon::create('wiki'));
+        if (!$this->page->isNew()) {
+            $this->contentbar->setInfo(sprintf(
                 _('Version %1$s, geändert von %2$s <br> am %3$s'),
                 $this->page->versionnumber,
                 sprintf(
@@ -128,33 +129,44 @@ class Course_WikiController extends AuthenticatedController
                 ),
                 date('d.m.Y H:i:s', $this->page['chdate'])
             ));
-        $action_menu = ActionMenu::get();
-        if ($this->page->isEditable()) {
-            $action_menu->addLink(
-                $this->editURL($this->page),
-                _('Bearbeiten'),
-                Icon::create('edit')
-            );
+            $action_menu = ActionMenu::get();
+            if ($this->page->isEditable()) {
+                $action_menu->addLink(
+                    $this->editURL($this->page),
+                    _('Bearbeiten'),
+                    Icon::create('edit')
+                );
+                $action_menu->addLink(
+                    $this->pagesettingsURL($this->page->id),
+                    _('Seiteneinstellungen'),
+                    Icon::create('settings'),
+                    ['data-dialog' => 'width=700']
+                );
+                if (count($this->page->versions) > 0) {
+                    $action_menu->addLink(
+                        $this->ask_deletingURL($this->page),
+                        _('Seite / Version löschen'),
+                        Icon::create('trash'),
+                        ['data-dialog' => 'size=auto']
+                    );
+                } else {
+                    $action_menu->addButton(
+                        'delete',
+                        _('Seite löschen'),
+                        Icon::create('trash'),
+                        ['data-confirm' => _('Wollen Sie wirklich die komplette Seite löschen?'), 'form' => 'delete_page']
+                    );
+                }
+            }
             $action_menu->addLink(
-                $this->pagesettingsURL($this->page->id),
-                _('Seiteneinstellungen'),
-                Icon::create('settings'),
-                ['data-dialog' => 'width=700']
-            );
-            $action_menu->addButton(
-                'delete',
-                _('Seite löschen'),
-                Icon::create('trash'),
-                ['data-confirm' => _('Wollen Sie wirklich die komplette Seite löschen?'), 'form' => 'delete_page']
+                '#',
+                _('Als Vollbild anzeigen'),
+                Icon::create('screen-full'),
+                ['class' => 'fullscreen-trigger hidden-medium-down']
             );
+            $this->contentbar->setActionMenu($action_menu);
         }
-        $action_menu->addLink(
-            '#',
-            _('Als Vollbild anzeigen'),
-            Icon::create('screen-full'),
-            ['class' => 'fullscreen-trigger hidden-medium-down']
-        );
-        $this->contentbar->setActionMenu($action_menu);
+
     }
 
     public function pagesettings_action(WikiPage $page)
@@ -253,7 +265,10 @@ class Course_WikiController extends AuthenticatedController
                     "[[ " . $values['name'],
                     $p2['content']
                 );
-                $p2->store();
+                if ($p2->isDirty()) {
+                    $p2['user_id'] = User::findCurrent()->id;
+                    $p2->store();
+                }
             }
         })->validate();
         if (Request::isPost()) {
@@ -269,9 +284,17 @@ class Course_WikiController extends AuthenticatedController
         $this->render_form($this->form);
     }
 
+    public function ask_deleting_action(WikiPage $page)
+    {
+        if (!$page->isEditable()) {
+            throw new AccessDeniedException();
+        }
+        PageLayout::setTitle(_('Was genau soll gelöscht werden?'));
+    }
+
     public function delete_action(WikiPage $page)
     {
-        if (!Request::isPost() || !CSRFProtection::verifyRequest()) {
+        if (!Request::isPost() || !$page->isEditable() || !CSRFProtection::verifyRequest()) {
             throw new AccessDeniedException();
         }
         $name = $page->name;
@@ -280,13 +303,52 @@ class Course_WikiController extends AuthenticatedController
         $this->redirect($this->allpagesURL());
     }
 
+    public function deleteversion_action(WikiPage $page, $version_id = null)
+    {
+        if (!Request::isPost() || !$page->isEditable() || !CSRFProtection::verifyRequest()) {
+            throw new AccessDeniedException();
+        }
+        if ($version_id === null) {
+            $version = $page->versions[0];
+            if ($version) {
+                $page['name'] = $version['name'];
+                $page['content'] = $version['content'];
+                $page['user_id'] = $version['user_id'];
+                $page['chdate'] = $version['mkdate'];
+                $page->store();
+                $version->delete();
+            } else {
+                $page->delete();
+            }
+        } else {
+            $version = WikiVersion::find($version_id);
+            if ($version['page_id'] === $page->id) {
+                $version->delete();
+            }
+        }
+        PageLayout::postSuccess(_('Version wurde gelöscht.'));
+        if (Request::get('redirect_to') === 'page') {
+            $this->redirect($this->page($page));
+        } else {
+            $this->redirect($this->history($page));
+        }
+
+    }
+
     public function allpages_action()
     {
-        Navigation::activateItem('/course/wiki/allpages');
         $this->pages = WikiPage::findBySQL(
             "`range_id` = ? ORDER BY `name` ASC",
             [$this->range->id]
         );
+
+        if (count($this->pages) === 0) {
+            $this->redirect($this->pageURL());
+            return;
+        }
+
+        Navigation::activateItem('/course/wiki/allpages');
+
         if ($GLOBALS['perm']->have_studip_perm('tutor', $this->range->id)) {
             $actions = new ActionsWidget();
             $actions->addLink(
@@ -379,7 +441,7 @@ class Course_WikiController extends AuthenticatedController
             $this->redirect($this->editURL($page));
             return;
         }
-        if (!$page->isEditable()) {
+        if ($page->isNew() || !$page->isEditable()) {
             throw new AccessDeniedException();
         }
         Navigation::activateItem('/course/wiki/start');
@@ -393,7 +455,7 @@ class Course_WikiController extends AuthenticatedController
         );
         $pageData = [
             'page_id' => $page->id,
-            'user_id' => $user->id
+            'user_id' => $user ? $user->id : null,
         ];
         $online_user = WikiOnlineEditingUser::findOneBySQL(
             '`page_id` = :page_id AND `user_id` = :user_id',
@@ -404,7 +466,7 @@ class Course_WikiController extends AuthenticatedController
         }
         $editingUsers = WikiOnlineEditingUser::countBySQL(
             "`page_id` = ? AND `editing` = 1 AND `user_id` != ?",
-            [$page->id, $user->id]
+            [$page->id, $user ? $user->id : null]
         );
         $online_user->editing = $editingUsers === 0 ? 1 : 0;
         $online_user->chdate = time();
@@ -501,6 +563,7 @@ class Course_WikiController extends AuthenticatedController
             $this->render_json([
                 'error' => 'user_not_requested_edit_mode'
             ]);
+            return;
         }
 
         $online_user_me->editing = 0;
@@ -524,7 +587,19 @@ class Course_WikiController extends AuthenticatedController
         }
 
         $page->content = \Studip\Markup::markAsHtml(trim(Request::get('content')));
-        $page->store();
+        $user = User::findCurrent();
+        if ($page->isDirty()) {
+            $page['user_id'] = $user->id;
+            $page->store();
+        }
+        $pageData = [
+            'page_id' => $page->id,
+            'user_id' => $user->id
+        ];
+        WikiOnlineEditingUser::deleteBySQL(
+            '`page_id` = :page_id AND `user_id` = :user_id',
+            $pageData
+        );
         PageLayout::postSuccess(_('Die Seite wurde gespeichert.'));
         $this->redirect($this->pageURL($page));
     }
@@ -560,7 +635,7 @@ class Course_WikiController extends AuthenticatedController
         $statement->execute([
             'range_id' => $this->range->id,
             'threshold' => $this->last_visit,
-            'me' => User::findCurrent()->id
+            'me' => User::findCurrent() ? User::findCurrent()->id : null
         ]);
         $this->num_entries = $statement->fetch(PDO::FETCH_COLUMN);
         $this->pagenumber = Request::int('page', 0);
@@ -754,6 +829,10 @@ class Course_WikiController extends AuthenticatedController
                         'type' => 'no',
                         'mapper' => function () { return $this->range->id; }
                     ],
+                    'user_id' => [
+                        'type' => 'no',
+                        'mapper' => function () { return User::findCurrent()->id; }
+                    ],
                     'name' => [
                         'required' => true,
                         'label' => _('Name der Seite'),
@@ -808,7 +887,10 @@ class Course_WikiController extends AuthenticatedController
                             '[[ ' . $values['name'] . ' ]]',
                             $page->content
                         );
-                        $page->store();
+                        if ($page->isDirty()) {
+                            $page['user_id'] = User::findCurrent()->id;
+                            $page->store();
+                        }
                     }
                 }
             }
@@ -894,6 +976,30 @@ class Course_WikiController extends AuthenticatedController
         Sidebar::Get()->addWidget($search);
     }
 
+    public function searchpage_action(WikiPage $page)
+    {
+        if (!$page->isReadable()) {
+            throw new AccessDeniedException();
+        }
+        Navigation::activateItem('/course/wiki/allpages');
+        if (!Request::get('search')) {
+            throw new Exception('No search text.');
+        }
+        $search = str_replace(['\\', '_', '%'], ['\\\\', '\\_', '\\%'], Request::get('search'));
+        $this->versions = WikiVersion::findBySQL("`page_id` = :page_id AND (`wiki_versions`.`content` LIKE :searchterm OR `wiki_versions`.`name` LIKE :searchterm) ORDER BY `mkdate` DESC ", [
+            'page_id' => $page->id,
+            'searchterm' => '%' . $search . '%'
+        ]);
+
+        $search = new SearchWidget($this->searchURL());
+        $search->addNeedle(
+            _('Im Wiki suchen'),
+            'search',
+            true
+        );
+        Sidebar::Get()->addWidget($search);
+    }
+
     public function pdf_action(WikiPage $page)
     {
         if (!$page->isReadable()) {
@@ -1135,4 +1241,41 @@ class Course_WikiController extends AuthenticatedController
 
         return $from_end ? mb_strlen($str0) - $length : $length;
     }
+
+    public function findTextualHits($text, $search, $length = 80)
+    {
+        $content = Studip\Markup::removeHtml($text);
+        $offset  = 0;
+        $output  = [];
+
+        // find all occurences
+        while ($offset < mb_strlen($content)) {
+            $pos = mb_stripos($content, Request::get('search'), $offset);
+            if ($pos === false) {
+                break;
+            }
+            $offset = $pos + 1;
+
+            // show max 200 chars
+            $fragment       = '';
+            $split_fragment = preg_split(
+                '/(' . preg_quote(Request::get('search'), '/') . ')/i',
+                mb_substr($content, max(0, $pos - floor($length / 2)), $length),
+                -1,
+                PREG_SPLIT_DELIM_CAPTURE
+            );
+            for ($i = 0; $i < count($split_fragment); ++$i) {
+                if ($i % 2) {
+                    $fragment .= '<span class="wiki_highlight">';
+                    $fragment .= htmlready($split_fragment[$i], false);
+                    $fragment .= '</span>';
+                } else {
+                    $fragment .= htmlready($split_fragment[$i], false);
+                }
+            }
+            $found_in_fragment = (count($split_fragment) - 1) / 2; // number of hits in fragment
+            $output[]          = '...' . $fragment . '...';
+        }
+        return implode('<br>', $output);
+    }
 }
diff --git a/app/controllers/course/wizard.php b/app/controllers/course/wizard.php
index b45f9e5..c1571ad 100644
--- a/app/controllers/course/wizard.php
+++ b/app/controllers/course/wizard.php
@@ -25,14 +25,9 @@ class Course_WizardController extends AuthenticatedController
     public function before_filter (&$action, &$args)
     {
         parent::before_filter($action, $args);
-        global $perm;
-        if (Request::isXhr()) {
-            $this->dialog = true;
-        }
-
-        $sidebar = Sidebar::get();
 
-        $this->studygroup = Request::int('studygroup') ?: $this->flash['studygroup'];
+        $this->dialog = Request::isXhr();
+        $this->studygroup = Request::bool('studygroup', $this->flash['studygroup'] ?? false);
 
         if (!$this->studygroup) {
             PageLayout::setTitle(_('Neue Veranstaltung anlegen'));
diff --git a/app/controllers/debugbar.php b/app/controllers/debugbar.php
new file mode 100644
index 0000000..59627f2
--- /dev/null
+++ b/app/controllers/debugbar.php
@@ -0,0 +1,24 @@
+<?php
+final class DebugbarController extends Trails_Controller
+{
+    public function __construct(
+        Trails\Dispatcher $dispatcher,
+        private readonly DebugBar\DebugBar $debugbar
+    ) {
+        parent::__construct($dispatcher);
+    }
+
+    public function css_action(): void
+    {
+        $this->set_content_type('text/css;charset=utf-8');
+        $this->render_nothing();
+        $this->debugbar->getJavascriptRenderer()->dumpCssAssets();
+    }
+
+    public function js_action(): void
+    {
+        $this->set_content_type('text/javascript;charset=utf-8');
+        $this->render_nothing();
+        $this->debugbar->getJavascriptRenderer()->setIncludeVendors(false)->dumpJsAssets();
+    }
+}
diff --git a/app/controllers/document.php b/app/controllers/document.php
index da15ebe..5057d9e 100644
--- a/app/controllers/document.php
+++ b/app/controllers/document.php
@@ -21,7 +21,7 @@ class DocumentController extends StudipController
         if ($file_ref) {
             $this->redirect($file_ref->getDownloadURL($disposition === 'inline' ? 'normal' : 'force'));
         } else {
-            throw new Trails_Exception(404);
+            throw new Trails\Exception(404);
         }
     }
 }
diff --git a/app/controllers/evaluation.php b/app/controllers/evaluation.php
deleted file mode 100644
index 4a157a9..0000000
--- a/app/controllers/evaluation.php
+++ /dev/null
@@ -1,61 +0,0 @@
-<?php
-
-# Lifter010: TODO
-/**
- * vote.php - Votecontroller controller
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- */
-
-class EvaluationController extends AuthenticatedController
-{
-    public function display_action($range_id)
-    {
-        // Bind some params
-        URLHelper::bindLinkParam('show_expired', $null1);
-
-        // Bind range_id
-        $this->range_id = $range_id;
-
-        $this->nobody = !$GLOBALS['user']->id || $GLOBALS['user']->id == 'nobody';
-
-        // Check if we ned administration icons
-        $this->admin = $range_id == $GLOBALS['user']->id || $GLOBALS['perm']->have_studip_perm('tutor', $range_id);
-
-        // Load evaluations
-        if (!$this->nobody) {
-            $eval_db = new EvaluationDB();
-            $this->evaluations = StudipEvaluation::findMany($eval_db->getEvaluationIDs($range_id, EVAL_STATE_ACTIVE));
-        } else {
-            $this->evaluations = [];
-        }
-        // Check if we got expired
-        if (Request::get('show_expired')) {
-            if ($this->admin) {
-                $this->evaluations = array_merge($this->evaluations, StudipEvaluation::findMany($eval_db->getEvaluationIDs($range_id, EVAL_STATE_STOPPED)));
-            }
-        }
-        if (!empty($this->suppress_empty_output) && count($this->evaluations) === 0) {
-            $this->render_nothing();
-        } else {
-            $this->visit();
-        }
-    }
-
-    public function visit()
-    {
-        if ($GLOBALS['user']->id && $GLOBALS['user']->id != 'nobody' && Request::option('contentbox_open') && in_array(Request::option('contentbox_type'), words('vote eval'))) {
-            object_set_visit(Request::option('contentbox_open'), Request::option('contentbox_type'));
-        }
-    }
-
-    public function visit_action()
-    {
-        $this->visit();
-        $this->render_nothing();
-    }
-
-}
diff --git a/app/controllers/extern.php b/app/controllers/extern.php
index 6cde6f3..9296a34 100644
--- a/app/controllers/extern.php
+++ b/app/controllers/extern.php
@@ -21,7 +21,7 @@ class ExternController extends StudipController
      * Action shows rendered external page.
      *
      * @param string $config_id The id of the configuration of the external page to show.
-     * @throws Trails_DoubleRenderError
+     * @throws Trails\Exceptions\DoubleRenderError
      */
     public function index_action(string $config_id)
     {
diff --git a/app/controllers/fachabschluss/kategorien.php b/app/controllers/fachabschluss/kategorien.php
index 205f1f1..f9ba041 100644
--- a/app/controllers/fachabschluss/kategorien.php
+++ b/app/controllers/fachabschluss/kategorien.php
@@ -114,7 +114,7 @@ class Fachabschluss_KategorienController extends MVVController
             if (Request::submitted('delete')) {
                 CSRFProtection::verifyUnsafeRequest();
                 if (!MvvPerm::get('AbschlussKategorie')->haveFieldPerm('position')) {
-                    throw new Trails_Exception(403);
+                    throw new Trails\Exception(403);
                 }
                 if (!count($abschluss_kategorie->abschluesse)) {
                     PageLayout::postSuccess(sprintf(
@@ -142,7 +142,7 @@ class Fachabschluss_KategorienController extends MVVController
         $orderedIds = Request::getArray('newOrder');
         if ($list === 'abschluss_kategorien') {
             if (!MvvPerm::get('AbschlussKategorie')->haveFieldPerm('position')) {
-                throw new Trails_Exception(403);
+                throw new Trails\Exception(403);
             }
             $kategorien = SimpleORMapCollection::createFromArray(
                 AbschlussKategorie::findBySql('1 ORDER BY position')
@@ -162,7 +162,7 @@ class Fachabschluss_KategorienController extends MVVController
             }
         } else {
             if (!MvvPerm::get('AbschlussZuord')->haveFieldPerm('position')) {
-                throw new Trails_Exception(403);
+                throw new Trails\Exception(403);
             }
             list(, $kategorie_id) = explode('_', $list);
             $abschluss_kategorie = AbschlussKategorie::find($kategorie_id);
diff --git a/app/controllers/file.php b/app/controllers/file.php
index 65344ef..376a74e 100644
--- a/app/controllers/file.php
+++ b/app/controllers/file.php
@@ -66,7 +66,7 @@ class FileController extends AuthenticatedController
             }
             $plugin = PluginManager::getInstance()->getPlugin(Request::get("from_plugin"));
             if (!$plugin) {
-                throw new Trails_Exception(404, _('Plugin existiert nicht.'));
+                throw new Trails\Exception(404, _('Plugin existiert nicht.'));
             }
             $folder = $plugin->getFolder($folder_id);
         } else {
@@ -184,10 +184,10 @@ class FileController extends AuthenticatedController
             //Plugin file area.
             $plugin = PluginManager::getInstance()->getPlugin($this->to_plugin);
             if (!$plugin) {
-                throw new Trails_Exception(404, _('Plugin existiert nicht.'));
+                throw new Trails\Exception(404, _('Plugin existiert nicht.'));
             }
             if (!($plugin instanceof FilesystemPlugin)) {
-                throw new Trails_Exception(400, _('Das Plugin ist kein Dateibereich-Plugin.'));
+                throw new Trails\Exception(400, _('Das Plugin ist kein Dateibereich-Plugin.'));
             }
             $file_ids = Request::getArray('file_refs');
             foreach ($file_ids as $file_id) {
@@ -294,7 +294,7 @@ class FileController extends AuthenticatedController
             }
             $plugin = PluginManager::getInstance()->getPlugin($this->from_plugin);
             if (!$plugin) {
-                throw new Trails_Exception(404, _('Plugin existiert nicht.'));
+                throw new Trails\Exception(404, _('Plugin existiert nicht.'));
             }
             $this->file = $plugin->getPreparedFile($file_id);
         } else {
@@ -364,7 +364,7 @@ class FileController extends AuthenticatedController
 
             //The file system object is a folder.
             //Calculate the files and the folder size:
-            list($this->folder_size, $this->folder_file_amount) = $this->getFolderSize($this->folder);
+            [$this->folder_size, $this->folder_file_amount] = $this->getFolderSize($this->folder);
             PageLayout::setTitle($this->folder->name);
             $this->render_action('folder_details');
         }
@@ -383,7 +383,7 @@ class FileController extends AuthenticatedController
             $file_ref_id = $file_id;
             $plugin = PluginManager::getInstance()->getPlugin(Request::get("from_plugin"));
             if (!$plugin) {
-                throw new Trails_Exception(404, _('Plugin existiert nicht.'));
+                throw new Trails\Exception(404, _('Plugin existiert nicht.'));
             }
 
             $this->file = $plugin->getPreparedFile($file_id);
@@ -666,7 +666,7 @@ class FileController extends AuthenticatedController
             }
             $plugin = PluginManager::getInstance()->getPlugin(Request::get("from_plugin"));
             if (!$plugin) {
-                throw new Trails_Exception(404, _('Plugin existiert nicht.'));
+                throw new Trails\Exception(404, _('Plugin existiert nicht.'));
             }
             $this->file = $plugin->getPreparedFile($file_id);
             $this->from_plugin = Request::get("from_plugin");
@@ -760,7 +760,7 @@ class FileController extends AuthenticatedController
 
             $plugin = PluginManager::getInstance()->getPlugin(Request::get("from_plugin"));
             if (!$plugin) {
-                throw new Trails_Exception(404, _('Plugin existiert nicht.'));
+                throw new Trails\Exception(404, _('Plugin existiert nicht.'));
             }
 
             $this->file_ref = $plugin->getPreparedFile($file_id);
@@ -814,7 +814,7 @@ class FileController extends AuthenticatedController
             }
             $plugin = PluginManager::getInstance()->getPlugin(Request::get("from_plugin"));
             if (!$plugin) {
-                throw new Trails_Exception(404, _('Plugin existiert nicht.'));
+                throw new Trails\Exception(404, _('Plugin existiert nicht.'));
             }
             $foldertype = $plugin->getFolder($folder_id);
 
@@ -980,7 +980,7 @@ class FileController extends AuthenticatedController
                 );
             } else {
                 $this->top_folder = $this->filesystemplugin->getFolder($folder_id, true);
-                if (is_a($this->top_folder, 'Flexi_Template')) {
+                if ($this->top_folder instanceof Flexi\Template) {
                     $this->top_folder->select    = true;
                     $this->top_folder->to_folder = $this->to_folder;
                     $this->render_text($this->top_folder);
@@ -1103,7 +1103,7 @@ class FileController extends AuthenticatedController
                     return;
                 }
 
-                $this->library_plugins = $plugin_manager->getPlugins('LibraryPlugin');
+                $this->library_plugins = $plugin_manager->getPlugins(LibraryPlugin::class);
 
                 //Build the query parameter array:
                 $search_parameters = [];
@@ -1128,7 +1128,7 @@ class FileController extends AuthenticatedController
 
                 $this->search_id = md5(json_encode($search_parameters));
 
-                $cache = StudipCacheFactory::getCache();
+                $cache = \Studip\Cache\Factory::getCache();
 
                 $merged_results = LibrarySearchManager::search(
                     $search_parameters,
@@ -1182,12 +1182,12 @@ class FileController extends AuthenticatedController
                 );
             }
         } elseif (Request::get('search_id')) {
-            $this->library_plugins = $plugin_manager->getPlugins('LibraryPlugin');
+            $this->library_plugins = $plugin_manager->getPlugins(LibraryPlugin::class);
 
             $this->search_id = Request::get('search_id');
             $this->page = Request::get('page');
 
-            $cache = StudipCacheFactory::getCache();
+            $cache = \Studip\Cache\Factory::getCache();
             $cache_data = $cache->read($this->search_id);
             $results = $cache_data['results'];
             $this->total_results = count($results);
@@ -1247,7 +1247,7 @@ class FileController extends AuthenticatedController
         }
 
         if ($item_id) {
-            $cache = StudipCacheFactory::getCache();
+            $cache = \Studip\Cache\Factory::getCache();
             $documents = $cache->read($search_id);
             $document = $documents['results'][$item_id];
             if (!($document instanceof LibraryDocument)) {
@@ -1255,7 +1255,7 @@ class FileController extends AuthenticatedController
             }
             $file = LibraryFile::createFromLibraryDocument($document, $folder_id);
         } else {
-            $cache = StudipCacheFactory::getCache();
+            $cache = \Studip\Cache\Factory::getCache();
             $search = $cache->read($search_id);
             if (!$search) {
                 throw new Exception('Search not found in cache!');
@@ -1325,7 +1325,7 @@ class FileController extends AuthenticatedController
             }
             $plugin = PluginManager::getInstance()->getPlugin(Request::get("from_plugin"));
             if (!$plugin) {
-                throw new Trails_Exception(404, _('Plugin existiert nicht.'));
+                throw new Trails\Exception(404, _('Plugin existiert nicht.'));
             }
             $filetype = $plugin->getPreparedFile($file_id);
             $folder = $filetype->getFolderType();
@@ -1335,7 +1335,7 @@ class FileController extends AuthenticatedController
             $filetype = $file_ref->getFileType();
         }
         if (!$filetype) {
-            throw new Trails_Exception(404, _('Datei nicht gefunden.'));
+            throw new Trails\Exception(404, _('Datei nicht gefunden.'));
         }
 
         if (!$filetype->isWritable($GLOBALS['user']->id)) {
@@ -1462,7 +1462,7 @@ class FileController extends AuthenticatedController
                 $this->current_folder = $this->to_folder_type;
                 $this->marked_element_ids = [];
 
-                $plugins = PluginManager::getInstance()->getPlugins('FileUploadHook');
+                $plugins = PluginManager::getInstance()->getPlugins(FileUploadHook::class);
 
                 $redirects = [];
                 foreach ($plugins as $plugin) {
@@ -1505,7 +1505,7 @@ class FileController extends AuthenticatedController
                     $folder_id = substr($folder_id, 0, strpos($folder_id, "?"));
                 }
                 $this->top_folder = $this->filesystemplugin->getFolder($folder_id, true);
-                if (is_a($this->top_folder, 'Flexi_Template')) {
+                if ($this->top_folder instanceof Flexi\Template) {
                     $this->top_folder->select    = true;
                     $this->top_folder->to_folder = $this->to_folder;
                     $this->render_text($this->top_folder->render());
@@ -1685,7 +1685,7 @@ class FileController extends AuthenticatedController
                         );
                     }
 
-                    $plugins = PluginManager::getInstance()->getPlugins('FileUploadHook');
+                    $plugins = PluginManager::getInstance()->getPlugins(FileUploadHook::class);
                     $redirect = null;
                     foreach ($plugins as $upload_hook_plugin) {
                         $url = $upload_hook_plugin->getAdditionalUploadWizardPage($file_ref);
@@ -1792,7 +1792,7 @@ class FileController extends AuthenticatedController
             }
             $plugin = PluginManager::getInstance()->getPlugin(Request::get("to_plugin"));
             if (!$plugin) {
-                throw new Trails_Exception(404, _('Plugin existiert nicht.'));
+                throw new Trails\Exception(404, _('Plugin existiert nicht.'));
             }
             $this->top_folder = $plugin->getFolder($folder_id);
         } else {
@@ -1820,7 +1820,7 @@ class FileController extends AuthenticatedController
 
                     $payload['html'][] = FilesystemVueDataManager::getFileVueData($this->file, $this->top_folder);
 
-                    $plugins = PluginManager::getInstance()->getPlugins('FileUploadHook');
+                    $plugins = PluginManager::getInstance()->getPlugins(FileUploadHook::class);
 
                     $redirects = [];
                     foreach ($plugins as $plugin) {
@@ -1857,7 +1857,7 @@ class FileController extends AuthenticatedController
             }
             $plugin = PluginManager::getInstance()->getPlugin(Request::get("from_plugin"));
             if (!$plugin) {
-                throw new Trails_Exception(404, _('Plugin existiert nicht.'));
+                throw new Trails\Exception(404, _('Plugin existiert nicht.'));
             }
             $parent_folder = $plugin->getFolder($folder_id);
         } else {
@@ -1963,7 +1963,7 @@ class FileController extends AuthenticatedController
             }
             $plugin = PluginManager::getInstance()->getPlugin(Request::get("from_plugin"));
             if (!$plugin) {
-                throw new Trails_Exception(404, _('Plugin existiert nicht.'));
+                throw new Trails\Exception(404, _('Plugin existiert nicht.'));
             }
             $folder = $plugin->getFolder($folder_id);
         } else {
@@ -2036,7 +2036,7 @@ class FileController extends AuthenticatedController
                 PageLayout::postMessage($result);
             }
         }
-        list($this->folder_size, $this->folder_file_amount) = $this->getFolderSize($folder);
+        [$this->folder_size, $this->folder_file_amount] = $this->getFolderSize($folder);
     }
 
     public function delete_folder_action($folder_id)
@@ -2050,7 +2050,7 @@ class FileController extends AuthenticatedController
             }
             $plugin = PluginManager::getInstance()->getPlugin(Request::get("from_plugin"));
             if (!$plugin) {
-                throw new Trails_Exception(404, _('Plugin existiert nicht.'));
+                throw new Trails\Exception(404, _('Plugin existiert nicht.'));
             }
             $folder = $plugin->getFolder($folder_id);
         } else {
@@ -2085,7 +2085,7 @@ class FileController extends AuthenticatedController
             }
             $plugin = PluginManager::getInstance()->getPlugin(Request::get("from_plugin"));
             if (!$plugin) {
-                throw new Trails_Exception(404, _('Plugin existiert nicht.'));
+                throw new Trails\Exception(404, _('Plugin existiert nicht.'));
             }
             $parent_folder = $plugin->getFolder($folder_id);
         } else {
diff --git a/app/controllers/files.php b/app/controllers/files.php
index 3c77f4e..df4657c 100644
--- a/app/controllers/files.php
+++ b/app/controllers/files.php
@@ -68,7 +68,7 @@ class FilesController extends AuthenticatedController
             $this->url_for("files/index"),
             Icon::create("files", "clickable")
         );
-        foreach (PluginManager::getInstance()->getPlugins('FilesystemPlugin') as $plugin) {
+        foreach (PluginManager::getInstance()->getPlugins(FilesystemPlugin::class) as $plugin) {
             if ($plugin->isPersonalFileArea()) {
                 $subnav = $plugin->getFileSelectNavigation();
                 $sources->addLink(
@@ -110,7 +110,7 @@ class FilesController extends AuthenticatedController
         }
 
         $config_urls = [];
-        foreach (PluginManager::getInstance()->getPlugins('FilesystemPlugin') as $plugin) {
+        foreach (PluginManager::getInstance()->getPlugins(FilesystemPlugin::class) as $plugin) {
             $url = $plugin->filesystemConfigurationURL();
             if ($url) {
                 $navigation = $plugin->getFileSelectNavigation();
@@ -647,7 +647,7 @@ class FilesController extends AuthenticatedController
         PageLayout::setTitle(_('Dateibereich zur Konfiguration auswählen'));
 
         $this->configure_urls = [];
-        foreach (PluginManager::getInstance()->getPlugins('FilesystemPlugin') as $plugin) {
+        foreach (PluginManager::getInstance()->getPlugins(FilesystemPlugin::class) as $plugin) {
             $url = $plugin->filesystemConfigurationURL();
             if ($url) {
                 $navigation = $plugin->getFileSelectNavigation();
@@ -711,7 +711,7 @@ class FilesController extends AuthenticatedController
 
             $destination_plugin = PluginManager::getInstance()->getPlugin($to_plugin);
             if (!$destination_plugin) {
-                throw new Trails_Exception(404, _('Plugin existiert nicht.'));
+                throw new Trails\Exception(404, _('Plugin existiert nicht.'));
             }
             $destination_folder = $destination_plugin->getFolder($destination_id);
         } else {
@@ -731,7 +731,7 @@ class FilesController extends AuthenticatedController
                 if ($from_plugin) {
                     $source_plugin = PluginManager::getInstance()->getPlugin($from_plugin);
                     if (!$source_plugin) {
-                        throw new Trails_Exception(404, _('Plugin existiert nicht.'));
+                        throw new Trails\Exception(404, _('Plugin existiert nicht.'));
                     }
                     if (Request::get("isfolder")) {
                         if ($source_folder = $source_plugin->getFolder($fileref)) {
diff --git a/app/controllers/institute/basicdata.php b/app/controllers/institute/basicdata.php
index fb1ce96..9c800fd 100644
--- a/app/controllers/institute/basicdata.php
+++ b/app/controllers/institute/basicdata.php
@@ -435,7 +435,7 @@ class Institute_BasicdataController extends AuthenticatedController
             }
 
             // delete all contents in forum-modules
-            foreach (PluginEngine::getPlugins('ForumModule') as $plugin) {
+            foreach (PluginEngine::getPlugins(ForumModule::class) as $plugin) {
                 $plugin->deleteContents($i_id);  // delete content irrespective of plugin-activation in the seminar
                 if ($plugin->isActivated($i_id)) {   // only show a message, if the plugin is activated, to not confuse the user
                     $details[] = sprintf(_('Einträge in %s gelöscht.'), $plugin->getPluginName());
diff --git a/app/controllers/institute/overview.php b/app/controllers/institute/overview.php
index 66d55e1..3713dcc 100644
--- a/app/controllers/institute/overview.php
+++ b/app/controllers/institute/overview.php
@@ -138,9 +138,6 @@ class Institute_OverviewController extends AuthenticatedController
 
         // Fetch  votes
         if (Config::get()->VOTE_ENABLE) {
-            $response = $this->relay('evaluation/display/' . $this->institute_id . '/institute');
-            $this->evaluations = $response->body;
-
             $response = $this->relay('questionnaire/widget/' . $this->institute_id . '/institute');
             $this->questionnaires = $response->body;
         }
diff --git a/app/controllers/jsupdater.php b/app/controllers/jsupdater.php
index eb6032d..a5425f9 100644
--- a/app/controllers/jsupdater.php
+++ b/app/controllers/jsupdater.php
@@ -290,71 +290,77 @@ class JsupdaterController extends AuthenticatedController
                     ]
                 );
                 $page = WikiPage::find($page_id);
-                if ($page && $page->isEditable()) {
-                    if (
-                        $pageInfo['wiki_editor_status']['focussed'] == $page_id
-                        && !empty($pageInfo['wiki_editor_status']['page_content'])
-                    ) {
-                        $page->content = \Studip\Markup::markAsHtml(
-                            $pageInfo['wiki_editor_status']['page_content']
+                if ($page) {
+                    if ($page->isEditable()) {
+                        if (
+                            $pageInfo['wiki_editor_status']['focussed'] == $page_id
+                            && !empty($pageInfo['wiki_editor_status']['page_content'])
+                        ) {
+                            $page->content = \Studip\Markup::markAsHtml(
+                                $pageInfo['wiki_editor_status']['page_content']
+                            );
+                            if ($page->isDirty()) {
+                                $page['user_id'] = User::findCurrent()->id;
+                                $page->store();
+                            }
+                        }
+                        $onlineData = [
+                            'user_id' => $user->id,
+                            'page_id' => $page_id
+                        ];
+                        $online     = WikiOnlineEditingUser::findOneBySQL(
+                            "`user_id` = :user_id AND `page_id` = :page_id",
+                            $onlineData
                         );
-                        $page->store();
-                    }
-                    $onlineData = [
-                        'user_id' => $user->id,
-                        'page_id' => $page_id
-                    ];
-                    $online = WikiOnlineEditingUser::findOneBySQL(
-                        "`user_id` = :user_id AND `page_id` = :page_id",
-                        $onlineData
-                    );
-                    if (!$online) {
-                        $online = WikiOnlineEditingUser::build($onlineData);
-                    }
-                    $editingUsers = WikiOnlineEditingUser::countBySQL(
-                        "`page_id` = ? AND `editing` = 1 AND `user_id` != ?",
-                        [$page->id, $user->id]
-                    );
-                    if ($editingUsers > 0) {
-                        $online->editing = 0;
-                    } elseif ($online->editing && $online->editing_request) {
-                        // this is the mode that this user requested the editing mode and was granted to get it:
-                        $online->editing_request = 0;
-                    } elseif ($online->editing_request) {
-                        $other_requests = WikiOnlineEditingUser::countBySql("`page_id` = ? AND `editing_request` = 1 AND `user_id` != ?", [
-                            $page->id,
-                            $user->id,
-                        ]);
-                        if ($other_requests === 0) {
-                            $online->editing_request = 0;
-                            $online->editing = 1;
+                        if (!$online) {
+                            $online = WikiOnlineEditingUser::build($onlineData);
                         }
-                    } else {
-                        if ($pageInfo['wiki_editor_status']['focussed'] == $page_id) {
-                            $online->editing = 1;
-                        } else {
-                            $other_users = WikiOnlineEditingUser::countBySql("`page_id` = ? AND `user_id` != ?", [
+                        $editingUsers = WikiOnlineEditingUser::countBySQL(
+                            "`page_id` = ? AND `editing` = 1 AND `user_id` != ?",
+                            [$page->id, $user->id]
+                        );
+                        if ($editingUsers > 0) {
+                            $online->editing = 0;
+                        } else if ($online->editing && $online->editing_request) {
+                            // this is the mode that this user requested the editing mode and was granted to get it:
+                            $online->editing_request = 0;
+                        } else if ($online->editing_request) {
+                            $other_requests = WikiOnlineEditingUser::countBySql("`page_id` = ? AND `editing_request` = 1 AND `user_id` != ?", [
                                 $page->id,
                                 $user->id,
                             ]);
-                            if ($other_users === 0) {
-                                // if I'm the only user I don't need to lose the edit mode
+                            if ($other_requests === 0) {
+                                $online->editing_request = 0;
+                                $online->editing         = 1;
+                            }
+                        } else {
+                            if ($pageInfo['wiki_editor_status']['focussed'] == $page_id) {
                                 $online->editing = 1;
                             } else {
-                                $online->editing = 0;
+                                $other_users = WikiOnlineEditingUser::countBySql("`page_id` = ? AND `user_id` != ?", [
+                                    $page->id,
+                                    $user->id,
+                                ]);
+                                if ($other_users === 0) {
+                                    // if I'm the only user I don't need to lose the edit mode
+                                    $online->editing = 1;
+                                } else {
+                                    $online->editing = 0;
+                                }
                             }
                         }
+                        $online->chdate = time();
+                        $online->store();
+                        $data['contents'][$page_id]         = wikiReady($page->content, true, $page->range_id, $page_id);
+                        $data['wysiwyg_contents'][$page_id] = $page->content;
+                        $data['pages'][$page_id]['editing'] = $online->editing;
+                    }
+                    else {
+                        $data['pages'][$page_id]['editing'] = 0;
                     }
-                    $online->chdate = time();
-                    $online->store();
-                    $data['contents'][$page_id] = wikiReady($page->content, true, $page->range_id, $page_id);
-                    $data['wysiwyg_contents'][$page_id] = $page->content;
-                    $data['pages'][$page_id]['editing'] = $online->editing;
-                } else {
-                    $data['pages'][$page_id]['editing'] = 0;
+                    $data['pages'][$page_id]['chdate'] = $page->chdate;
+                    $data['users'][$page_id] = $page->getOnlineUsers();
                 }
-                $data['pages'][$page_id]['chdate'] = $page->chdate;
-                $data['users'][$page_id] = $page->getOnlineUsers();
             }
         }
         return $data;
diff --git a/app/controllers/loncapa.php b/app/controllers/loncapa.php
index 3119178..dd7ea40 100644
--- a/app/controllers/loncapa.php
+++ b/app/controllers/loncapa.php
@@ -1,6 +1,4 @@
 <?php
-require_once 'app/controllers/authenticated_controller.php';
-
 class LoncapaController extends AuthenticatedController
 {
     public function enter_action()
@@ -15,8 +13,8 @@ class LoncapaController extends AuthenticatedController
         if ($GLOBALS['perm']->have_studip_perm('user', $course_id)
             && isset($GLOBALS['ELEARNING_INTERFACE_MODULES'][$cms_type]))
         {
-            require_once 'lib/elearning/ELearningUtils.class.php';
-            require_once 'lib/elearning/ObjectConnections.class.php';
+            require_once 'lib/elearning/ELearningUtils.php';
+            require_once 'lib/elearning/ObjectConnections.php';
 
             $object_connections = new ObjectConnections($course_id);
             $connected_modules = $object_connections->getConnections();
diff --git a/app/controllers/lvgruppen/lvgruppen.php b/app/controllers/lvgruppen/lvgruppen.php
index 5bac0fd..8562836 100644
--- a/app/controllers/lvgruppen/lvgruppen.php
+++ b/app/controllers/lvgruppen/lvgruppen.php
@@ -149,10 +149,12 @@ class Lvgruppen_LvgruppenController extends MVVController
             $semester = Semester::find($this->semester_filter);
             if ($semester && $semester->isCurrent()) {
                 $this->next_sem = Semester::findNext();
-                $this->display_semesters[] = $this->next_sem;
-                $this->courses = array_merge($this->courses,
-                    $this->lvgruppe->getAllAssignedCourses(false, $this->next_sem->id)
-                );
+                if ($this->next_sem) {
+                    $this->display_semesters[] = $this->next_sem;
+                    $this->courses = array_merge($this->courses,
+                        $this->lvgruppe->getAllAssignedCourses(false, $this->next_sem->id)
+                    );
+                }
             }
             $this->current_sem = $semester;
             $this->display_semesters[] = $semester;
@@ -451,7 +453,7 @@ class Lvgruppen_LvgruppenController extends MVVController
         );
         $widget->class = 'nested-select';
         $widget->addElement(
-            new SelectElement('select-none', _('Alle'), $selected_abschlussh === '')
+            new SelectElement('select-none', _('Alle'), $selected_abschluss === '')
         );
         $abschluesse = Abschluss::findBySQL(' 1 ORDER BY `name`');
         foreach ($abschluesse as $abschluss) {
@@ -533,11 +535,12 @@ class Lvgruppen_LvgruppenController extends MVVController
     private function set_trails_filter($start, $end)
     {
         // show only pathes with modules valid in the selected semester
-        ModuleManagementModelTreeItem::setObjectFilter('Modulteil',
+        ModuleManagementModelTreeItem::setObjectFilter(
+            Modulteil::class,
             function ($mt) use ($start, $end) {
-                $modul_start = Semester::find($mt->modul->start)->beginn ?: 0;
-                $modul_end = Semester::find($mt->modul->end)->ende ?: PHP_INT_MAX;
-                return ($modul_start <= $end && $modul_end >= $start);
+                $modul_start = Semester::find($mt->modul->start)->beginn ?? 0;
+                $modul_end = Semester::find($mt->modul->end)->ende ?? PHP_INT_MAX;
+                return $modul_start <= $end && $modul_end >= $start;
             }
         );
     }
diff --git a/app/controllers/materialien/files.php b/app/controllers/materialien/files.php
index 804668e..429a98c 100644
--- a/app/controllers/materialien/files.php
+++ b/app/controllers/materialien/files.php
@@ -362,29 +362,37 @@ class Materialien_FilesController extends MVVController
 
     public function upload_attachment_action()
     {
-        if ($GLOBALS['user']->id === "nobody") {
+        $user = User::findCurrent();
+        if (!$user) {
             throw new AccessDeniedException();
         }
 
-        $file = $_FILES['file'];
-        $output = [
-            'name' => $file['name'],
-            'size' => $file['size']];
-
         $mvvfile_id = Request::option('mvvfile_id');
-        $output['mvvfile_id'] = $mvvfile_id;
-        $range_id = Request::option('range_id', $mvvfile_id);
-        $output['range_id'] = $range_id;
-        $file_language = Request::option('file_language');
+        $document_id = Request::option('document_id');
 
-        $top_folder = $this->getTopFolder($mvvfile_id);
-
-        $user = User::findCurrent();
-
-        $file = StandardFile::create($_FILES['file']);
-        $error = $top_folder->validateUpload($file, $GLOBALS['user']->id);
-        if ($error != null) {
-            $file->delete();
+        $file = $_FILES['file'];
+        $output = [
+            'name'       => $file['name'],
+            'size'       => $file['size'],
+            'mvvfile_id' => $mvvfile_id,
+            'range_id'   => Request::option('range_id', $mvvfile_id),
+        ];
+
+        $top_folder = $this->getTopFolder($output['mvvfile_id']);
+
+        if ($document_id) {
+            $file = File::find($document_id);
+            $file->mime_type = $_FILES['file']['type'] ?? get_mime_type($_FILES['file']['name']);
+            $file->size = $_FILES['file']['size'] ?? filesize($_FILES['file']['tmp_name']);
+            $file->connectWithDataFile($_FILES['file']['tmp_name']);
+        } else {
+            $file = StandardFile::create($_FILES['file']);
+        }
+        $error = $top_folder->validateUpload($file, $user->id);
+        if ($error !== null) {
+            if (!$document_id) {
+                $file->delete();
+            }
             $this->response->set_status(400);
             $this->render_json(compact('error'));
             return;
@@ -399,18 +407,15 @@ class Materialien_FilesController extends MVVController
             return;
         }
 
-        $mvv_file_fileref = new MvvFileFileref([$mvvfile_id, $file_language]);
-        $mvv_file_fileref->fileref_id = $file->getId();
+        $mvv_file_fileref = new MvvFileFileref([
+            $output['mvvfile_id'],
+            Request::option('file_language'),
+        ]);
+        $mvv_file_fileref->fileref_id = $file->id;
         $mvv_file_fileref->store();
 
-        $output['document_id'] = $file->getId();
-
-        $output['icon'] = Icon::create(
-            FileManager::getIconNameForMimeType(
-                $file->getMimeType()
-            ),
-            'clickable'
-        )->asImg(['class' => "text-bottom"]);
+        $output['document_id'] = $file->id;
+        $output['icon'] = $file->getIcon(Icon::ROLE_CLICKABLE)->asImg(['class' => 'text-bottom']);
 
         $this->render_json($output);
     }
@@ -510,7 +515,7 @@ class Materialien_FilesController extends MVVController
 
         $mvv_file = MvvFile::find($mvvfile_id);
         if (!$mvv_file) {
-            throw new Trails_Exception(404);
+            throw new Trails\Exception(404);
         }
 
         $this->doc_year = $mvv_file->year;
diff --git a/app/controllers/media_proxy.php b/app/controllers/media_proxy.php
index 50dc3df..b98b49c 100644
--- a/app/controllers/media_proxy.php
+++ b/app/controllers/media_proxy.php
@@ -46,7 +46,7 @@ class MediaProxyController extends StudipController
         ini_set('default_socket_timeout', 5);
         $this->render_nothing();
 
-        //stop output buffering started in Trails_Dispatcher::dispatch()
+        //stop output buffering started in Trails\Dispatcher::dispatch()
         while (ob_get_level()) {
             ob_end_clean();
         }
diff --git a/app/controllers/module/module.php b/app/controllers/module/module.php
index 2f6ba4c..854b045 100644
--- a/app/controllers/module/module.php
+++ b/app/controllers/module/module.php
@@ -53,7 +53,7 @@ class Module_ModuleController extends MVVController
         if (count($search_result) > 0) {
             $module_ids = $search_result;
         } else {
-            if ($_SESSION['mvv_filter_module_fach_id']) {
+            if (!empty($_SESSION['mvv_filter_module_fach_id'])) {
                 $module_ids = $this->findModuleIdsByFach($_SESSION['mvv_filter_module_fach_id']);
             }
             if (!empty($_SESSION['mvv_filter_module_abschluss_id'])) {
@@ -395,17 +395,17 @@ class Module_ModuleController extends MVVController
      * Deletes a descriptor from module
      *
      * @param type $deskriptor_id
-     * @throws Trails_Exception
+     * @throws Trails\Exception
      */
     public function delete_modul_deskriptor_action($deskriptor_id, $language)
     {
         $deskriptor = ModulDeskriptor::find($deskriptor_id);
         if (is_null($deskriptor)) {
-            throw new Trails_Exception(404, _('Unbekannter Deskriptor'));
+            throw new Trails\Exception(404, _('Unbekannter Deskriptor'));
         }
         $def_lang = $deskriptor->modul->getDefaultLanguage();
         if ($language === $def_lang) {
-            throw new Trails_Exception(403, _('Ein Deskriptor in der Original-Sprache kann nicht gelöscht werden.'));
+            throw new Trails\Exception(403, _('Ein Deskriptor in der Original-Sprache kann nicht gelöscht werden.'));
         }
         if (Request::submitted('delete')) {
             CSRFProtection::verifyUnsafeRequest();
@@ -819,17 +819,17 @@ class Module_ModuleController extends MVVController
      * Deletes a descriptor from Modulteil
      *
      * @param type $deskriptor_id
-     * @throws Trails_Exception
+     * @throws Trails\Exception
      */
     public function delete_modulteil_deskriptor_action($deskriptor_id, $language)
     {
         $deskriptor = ModulteilDeskriptor::find($deskriptor_id);
         if (is_null($deskriptor)) {
-            throw new Trails_Exception(404, _('Unbekannter Deskriptor'));
+            throw new Trails\Exception(404, _('Unbekannter Deskriptor'));
         }
         $def_lang = $deskriptor->modulteil->getDefaultLanguage();
         if ($language === $def_lang) {
-            throw new Trails_Exception(403, _('Ein Deskriptor in der Original-Sprache kann nicht gelöscht werden.'));
+            throw new Trails\Exception(403, _('Ein Deskriptor in der Original-Sprache kann nicht gelöscht werden.'));
         }
         if (Request::submitted('delete')) {
             CSRFProtection::verifyUnsafeRequest();
diff --git a/app/controllers/module/mvv_controller.php b/app/controllers/module/mvv_controller.php
index e84b37c..b70ddef 100644
--- a/app/controllers/module/mvv_controller.php
+++ b/app/controllers/module/mvv_controller.php
@@ -77,7 +77,7 @@ abstract class MVVController extends AuthenticatedController
         PageLayout::setTitle(_('Module'));
 
         // Setup flash instance
-        $this->flash = Trails_Flash::instance();
+        $this->flash = Trails\Flash::instance();
 
         $this->me             = 'mvv';
         self::$items_per_page = Config::get()->getValue('ENTRIES_PER_PAGE');
@@ -218,7 +218,7 @@ abstract class MVVController extends AuthenticatedController
      * This action is used to show a select box instead of an input field
      * if the user has clicked on the magnifier icon of a quicksearch.
      *
-     * @throws Trails_Exception
+     * @throws Trails\Exception
      */
     public function qs_result_action()
     {
@@ -228,7 +228,7 @@ abstract class MVVController extends AuthenticatedController
                 Request::get('qs_term')
             ));
         } else {
-            throw new Trails_Exception(404);
+            throw new Trails\Exception(404);
         }
     }
 
diff --git a/app/controllers/my_courses.php b/app/controllers/my_courses.php
index 410947b..8205c12 100644
--- a/app/controllers/my_courses.php
+++ b/app/controllers/my_courses.php
@@ -131,26 +131,16 @@ class MyCoursesController extends AuthenticatedController
             throw new AccessDeniedException();
         }
 
-        $this->with_modules = Request::bool('modules');
-
-        $this->sem_data = Semester::getAllAsArray();
-
-        $this->group_field = 'sem_number';
-
-        // Needed parameters for selecting courses
-        $params = [
-            'group_field'         => $this->group_field,
+        $template = $this->get_template_factory()->open('my_courses/courseexport');
+        $template->sem_courses = MyRealmModel::getPreparedCourses('', [
+            'group_field'         => 'sem_number',
             'order_by'            => null,
             'order'               => 'asc',
             'studygroups_enabled' => Config::get()->MY_COURSES_ENABLE_STUDYGROUPS,
             'deputies_enabled'    => Config::get()->DEPUTIES_ENABLE,
-        ];
-
-        $this->sem_courses  = MyRealmModel::getPreparedCourses('all', $params);
-
-        $factory  = $this->get_template_factory();
-        $template = $factory->open('my_courses/courseexport');
-        $template->set_attributes($this->get_assigned_variables());
+        ]);
+        $template->sem_data = Semester::getAllAsArray();
+        $template->with_modules = Request::bool('modules');
         $template->image_style = 'height: 6px; width: 8px;';
 
         $doc = new ExportPDF();
@@ -200,7 +190,7 @@ class MyCoursesController extends AuthenticatedController
                            LEFT JOIN `mvv_lvgruppe` AS ml ON (mls.`lvgruppe_id` = ml.`lvgruppe_id`)
                            LEFT JOIN `mvv_lvgruppe_modulteil` AS mlm on(mls.`lvgruppe_id` = mlm.`lvgruppe_id`)
                            LEFT JOIN `mvv_modulteil` AS mmt ON (mlm.`modulteil_id` = mmt.`modulteil_id`)
-                           LEFT JOIN `mvv_modul` AS mm ON (mmt.`modul_id` = mm.`modul_id`)";
+                           LEFT JOIN `mvv_modul` AS mm ON (mmt.`modul_id` = mm.`modul_id` AND mm.`stat` = 'genehmigt')";
 
         }
 
@@ -354,7 +344,10 @@ class MyCoursesController extends AuthenticatedController
         $semesters   = MyRealmModel::getSelectedSemesters($sem);
         $min_sem_key = min($semesters);
         $max_sem_key = max($semesters);
-        $courses     = MyRealmModel::getCourses($min_sem_key, $max_sem_key, compact('deputies_enabled'));
+        $courses     = MyRealmModel::getCourses($min_sem_key, $max_sem_key, [
+            'deputies_enabled' => $deputies_enabled,
+            'exactly'          => $semesters,
+        ]);
         foreach ($courses as $index => $course) {
             MyRealmModel::setObjectVisits($course, $GLOBALS['user']->id, $timestamp);
         }
@@ -1178,6 +1171,7 @@ class MyCoursesController extends AuthenticatedController
             'future'      => _('Aktuelles und nächstes Semester'),
             'last'        => _('Aktuelles und letztes Semester'),
             'lastandnext' => _('Letztes, aktuelles, nächstes Semester'),
+            'lastbutone'  => _('Aktuelles und vorletztes Semester'),
         ];
 
         if (Config::get()->MY_COURSES_ENABLE_ALL_SEMESTERS) {
diff --git a/app/controllers/new_password.php b/app/controllers/new_password.php
index 525d73b..1e58659 100644
--- a/app/controllers/new_password.php
+++ b/app/controllers/new_password.php
@@ -41,36 +41,32 @@ class NewPasswordController extends StudipController
 
         $users = User::findByEmail(Request::get('mail'));
 
-        if (sizeof($users) == 1) {
-            $user = $users[0];
-        } else if (sizeof($users) > 1) {
-            setTempLanguage($users[0]->id);
-
-            // there are mutliple accounts with this mail addresses!
-            $subject = sprintf(
-                _("[Stud.IP - %s] Passwortänderung angefordert"),
-                Config::get()->UNI_NAME_CLEAN
-            );
-
-            $mailbody = sprintf(
-                _("Dies ist eine Informationsmail des Stud.IP-Systems\n"
-                    ."(Studienbegleitender Internetsupport von Präsenzlehre)\n- %s -\n\n"
-                    . "Für die Mail-Adresse %s wurde ein Link angefordert\n"
-                    . "um das Passwort zurückzusetzen.\n"
-                    . "Dieser Mail-Adresse sind jedoch mehrere Zugänge zugeordnet,\n"
-                    . "deshalb ist es nicht möglich, das Passwort hierüber zurückzusetzen.\n"
-                    . "Wenden sie sich bitte stattdessen an\n%s"
-                ),
-                Config::get()->UNI_NAME_CLEAN,
-                $users[0]->email,
-                $GLOBALS['UNI_CONTACT']
-            );
-
-            StudipMail::sendMessage($users[0]->email, $subject, $mailbody);
-
-            restoreLanguage();
-        }
-
+        $user = $users[0];
+        setTempLanguage($user->id);
+
+        // there are mutliple accounts with this mail addresses!
+        $subject = sprintf(
+            _("[Stud.IP - %s] Passwortänderung angefordert"),
+            Config::get()->UNI_NAME_CLEAN
+        );
+
+        $mailbody = sprintf(
+            _("Dies ist eine Informationsmail des Stud.IP-Systems\n"
+                ."(Studienbegleitender Internetsupport von Präsenzlehre)\n- %s -\n\n"
+                . "Für die Mail-Adresse %s wurde ein Link angefordert\n"
+                . "um das Passwort zurückzusetzen.\n"
+                . "Dieser Mail-Adresse sind jedoch mehrere Zugänge zugeordnet,\n"
+                . "deshalb ist es nicht möglich, das Passwort hierüber zurückzusetzen.\n"
+                . "Wenden sie sich bitte stattdessen an\n%s"
+            ),
+            Config::get()->UNI_NAME_CLEAN,
+            $users[0]->email,
+            $GLOBALS['UNI_CONTACT']
+        );
+
+        StudipMail::sendMessage($user->email, $subject, $mailbody);
+
+        restoreLanguage();
         if ($user) {
             // spam/abuse-protection
             // if there are more than 5 tokens present, do NOT send another mail
diff --git a/app/controllers/notifications.php b/app/controllers/notifications.php
index b206df1..dc31aab 100644
--- a/app/controllers/notifications.php
+++ b/app/controllers/notifications.php
@@ -13,9 +13,6 @@
  * @since       3.0
  */
 
-require_once 'app/controllers/authenticated_controller.php';
-
-
 class NotificationsController extends AuthenticatedController
 {
     /**
diff --git a/app/controllers/oer/endpoints.php b/app/controllers/oer/endpoints.php
index 417f1e8..1ce9626 100644
--- a/app/controllers/oer/endpoints.php
+++ b/app/controllers/oer/endpoints.php
@@ -45,7 +45,7 @@ class Oer_EndpointsController extends StudipController
         $this->render_json([
             'name' => Config::get()->UNI_NAME_CLEAN,
             'public_key' => $host['public_key'],
-            'url' => $GLOBALS['OER_PREFERRED_URI'] ?: $GLOBALS['ABSOLUTE_URI_STUDIP']."dispatch.php/oer/endpoints/",
+            'url' => ($GLOBALS['OER_PREFERRED_URI'] ?? $GLOBALS['ABSOLUTE_URI_STUDIP']) . 'dispatch.php/oer/endpoints/',
             'index_server' => $host['index_server']
         ]);
     }
@@ -254,7 +254,7 @@ class Oer_EndpointsController extends StudipController
                     'description' => $material['description'],
                     'content_type' => $material['content_type'],
                     'front_image_content_type' => $material['front_image_content_type'],
-                    'url' => ($GLOBALS['OER_PREFERRED_URI'] ?: $GLOBALS['ABSOLUTE_URI_STUDIP'])."dispatch.php/oer/market/download/".$item_id,
+                    'url' => ($GLOBALS['OER_PREFERRED_URI'] ?? $GLOBALS['ABSOLUTE_URI_STUDIP']) . 'dispatch.php/oer/market/download/' . $item_id,
                     'player_url' => $material['player_url'],
                     'tool' => $material['tool'],
                     'structure' => ($material['structure'] ? $material['structure']->getArrayCopy() : null),
@@ -374,7 +374,7 @@ class Oer_EndpointsController extends StudipController
 
         header("Expires: Mon, 12 Dec 2001 08:00:00 GMT");
         header("Last-Modified: " . gmdate ("D, d M Y H:i:s") . " GMT");
-        if ($_SERVER['HTTPS'] == "on") {
+        if (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] === 'on') {
             header("Pragma: public");
             header("Cache-Control: private");
         } else {
@@ -410,7 +410,7 @@ class Oer_EndpointsController extends StudipController
             $this->response->add_header('Content-Length', filesize($this->material->getFrontImageFilePath()));
             $this->render_text(file_get_contents($this->material->getFrontImageFilePath()));
         } else {
-            throw new Trails_Exception(404);
+            throw new Trails\Exception(404);
         }
     }
 
diff --git a/app/controllers/plugin_controller.php b/app/controllers/plugin_controller.php
deleted file mode 100644
index d57a90d..0000000
--- a/app/controllers/plugin_controller.php
+++ /dev/null
@@ -1,72 +0,0 @@
-<?php
-/**
- * Copyright (c) 2014  Rasmus Fuhse <fuhse@data-quest.de>
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- */
-
-class PluginController extends StudipController
-{
-    public function __construct($dispatcher)
-    {
-        parent::__construct($dispatcher);
-
-        if (!isset($dispatcher->current_plugin)) {
-            throw new Exception('Plugin missing for plugin controller!');
-        }
-        $this->plugin = $dispatcher->current_plugin;
-
-        if ($this->plugin && $this->plugin->hasTranslation()) {
-            // Localization
-            $this->_ = function ($string) {
-                return call_user_func_array(
-                    [$this->plugin, '_'],
-                    func_get_args()
-                );
-            };
-
-            $this->_n = function ($string0, $tring1, $n) {
-                return call_user_func_array(
-                    [$this->plugin, '_n'],
-                    func_get_args()
-                );
-            };
-        }
-    }
-
-    /**
-     * Creates the body element id for this controller a given action.
-     *
-     * @param string $unconsumed_path Unconsumed path to extract action from
-     * @return string
-     */
-    protected function getBodyElementIdForControllerAndAction($unconsumed_path)
-    {
-        $body_id = implode('-', [
-            'plugin',
-            strtosnakecase(get_class($this->plugin)),
-            parent::getBodyElementIdForControllerAndAction($unconsumed_path),
-        ]);
-
-        return $body_id;
-    }
-
-    /**
-     * Intercepts all non-resolvable method calls in order to correctly handle
-     * calls to _ and _n.
-     *
-     * @param string $method
-     * @param array  $arguments
-     * @return mixed
-     */
-    public function __call($method, $arguments)
-    {
-        if (isset($this->_template_variables[$method]) && is_callable($this->_template_variables[$method])) {
-            return call_user_func_array($this->_template_variables[$method], $arguments);
-        }
-        return parent::__call($method, $arguments);
-    }
-}
diff --git a/app/controllers/privacy.php b/app/controllers/privacy.php
index ba8e6f1..d50b1f1 100644
--- a/app/controllers/privacy.php
+++ b/app/controllers/privacy.php
@@ -305,7 +305,7 @@ class PrivacyController extends AuthenticatedController
             $storage->addFileRef($fileref);
         }
 
-        foreach (PluginEngine::getPlugins('PrivacyPlugin') as $plugin) {
+        foreach (PluginEngine::getPlugins(PrivacyPlugin::class) as $plugin) {
             $plugin->exportUserData($storage);
         }
 
diff --git a/app/controllers/profile.php b/app/controllers/profile.php
index a4e7c56a..1412c9c 100644
--- a/app/controllers/profile.php
+++ b/app/controllers/profile.php
@@ -37,22 +37,17 @@ class ProfileController extends AuthenticatedController
             'username',
             $this->user ? $this->user->username : null
         ));
-        // get additional informations to selected user
-        $this->profile = new ProfileModel(
-            $this->current_user ? $this->current_user->id : null,
-            $this->user ? $this->user->id : null
-        );
 
         // set the page title depending on user selection
         if (
-            $this->user
+            isset($this->user, $this->current_user)
             && $this->current_user->id === $this->user->id
             && !$this->current_user->locked
         ) {
             PageLayout::setTitle(_('Mein Profil'));
             UserConfig::get($this->user->id)->store('PROFILE_LAST_VISIT', time());
         } elseif (
-            $this->current_user->id
+            !empty($this->current_user->id)
             && (
                 $this->perm->have_perm('root')
                 || (
@@ -106,11 +101,11 @@ class ProfileController extends AuthenticatedController
 
         // Additional user information
         $this->public_email = get_visible_email($this->current_user->user_id);
-        $this->motto        = $this->profile->getVisibilityValue('motto');
-        $this->private_nr   = $this->profile->getVisibilityValue('privatnr', 'private_phone');
-        $this->private_cell = $this->profile->getVisibilityValue('privatcell', 'private_cell');
-        $this->privadr      = $this->profile->getVisibilityValue('privadr', 'privadr');
-        $this->homepage     = $this->profile->getVisibilityValue('Home', 'homepage');
+        $this->motto        = $this->getVisibilityValue('motto');
+        $this->private_nr   = $this->getVisibilityValue('privatnr', 'private_phone');
+        $this->private_cell = $this->getVisibilityValue('privatcell', 'private_cell');
+        $this->privadr      = $this->getVisibilityValue('privadr', 'privadr');
+        $this->homepage     = $this->getVisibilityValue('Home', 'homepage');
 
         // skype informations
         $this->skype_name = '';
@@ -119,8 +114,8 @@ class ProfileController extends AuthenticatedController
         }
 
         // get generic datafield entries
-        $this->shortDatafields = $this->profile->getShortDatafields();
-        $this->longDatafields  = $this->profile->getLongDatafields();
+        $this->shortDatafields = $this->getShortDatafields();
+        $this->longDatafields  = $this->getLongDatafields();
 
         // get working station of an user (institutes)
         $this->institutes = $this->getInstitutInformation();
@@ -144,24 +139,20 @@ class ProfileController extends AuthenticatedController
         }
 
         // calendar
-        $this->dates = '';
-        if (Config::get()->CALENDAR_ENABLE) {
-            if (!in_array($this->current_user->perms, ['admin', 'root'])) {
-                if (Visibility::verify('termine', $this->current_user->user_id)) {
-                    $start = time();
-                    $end   = strtotime('+1 week 23:59:59');
-
-                    $response    = $this->relay('calendar/contentbox/display/' . $this->current_user->user_id . '/' . ($end - $start));
-                    $this->dates = $response->body;
-                }
-            }
+        if (
+            Config::get()->CALENDAR_ENABLE
+            && !in_array($this->current_user->perms, ['admin', 'root'])
+            && Visibility::verify('termine', $this->current_user->user_id)
+        ) {
+            $start = time();
+            $end   = strtotime('+1 week 23:59:59');
+
+            $response    = $this->relay('calendar/contentbox/display/' . $this->current_user->user_id . '/' . ($end - $start));
+            $this->dates = $response->body;
         }
 
         // include and show votes and tests
         if (Config::get()->VOTE_ENABLE && Visibility::verify('votes', $this->current_user->user_id)) {
-            $response          = $this->relay('evaluation/display/' . $this->current_user->user_id);
-            $this->evaluations = $response->body;
-
             $response             = $this->relay('questionnaire/widget/' . $this->current_user->user_id . "/user");
             $this->questionnaires = $response->body;
         }
@@ -209,11 +200,11 @@ class ProfileController extends AuthenticatedController
 
         // Anzeige der Seminare, falls User = dozent
         if ($this->current_user['perms'] == 'dozent') {
-            $this->seminare = array_filter($this->profile->getDozentSeminars());
+            $this->seminare = array_filter($this->getTeacherSeminars());
         }
 
         // Hompageplugins
-        $homepageplugins = PluginEngine::getPlugins('HomepagePlugin');
+        $homepageplugins = PluginEngine::getPlugins(HomepagePlugin::class);
 
         $render = '';
         $layout = $GLOBALS['template_factory']->open('shared/content_box');
@@ -223,7 +214,7 @@ class ProfileController extends AuthenticatedController
                 $template = $homepageplugin->getHomepageTemplate($this->current_user->user_id);
                 // create output of the plugins
                 if (!empty($template)) {
-                    $render .= $template->render(null, $layout);
+                    $render .= $template->render(layout: $layout);
                 }
                 $layout->clear_attributes();
             }
@@ -237,7 +228,7 @@ class ProfileController extends AuthenticatedController
         foreach ($category as $cat) {
             $head = $cat->name;
             $body = $cat->content;
-            $vis_text = "";
+            $vis_text = '';
 
             if ($this->user->user_id == $this->current_user->user_id) {
                 $vis_text .= ' (' . Visibility::getStateDescription('kat_' . $cat->kategorie_id) . ')';
@@ -524,4 +515,155 @@ class ProfileController extends AuthenticatedController
         PageLayout::setTitle(sprintf(_('Profil von %s'), $external_user['name']));
         $this->user = $external_user;
     }
+
+    /**
+     * Collect user datafield informations
+     *
+     * @return array
+     */
+    private function getDatafields(): array
+    {
+        $short_datafields = [];
+        $long_datafields  = [];
+        foreach (DataFieldEntry::getDataFieldEntries($this->current_user->user_id, 'user') as $entry) {
+            if ($entry->isVisible() && $entry->getDisplayValue()
+                && Visibility::verify($entry->getID(), $this->current_user->user_id))
+            {
+                if ($entry instanceof DataFieldTextareaEntry) {
+                    $long_datafields[] = $entry;
+                } else {
+                    $short_datafields[] = $entry;
+                }
+            }
+        }
+
+        return [
+            'long'  => $long_datafields,
+            'short' => $short_datafields,
+        ];
+    }
+
+    /**
+     * Filter long datafiels from the datafields
+     *
+     * @return array
+     */
+    private function getLongDatafields(): array
+    {
+        $datafields = $this->getDatafields();
+        $array      = [];
+
+        if (!empty($datafields)) {
+            foreach ($datafields['long'] as $entry) {
+                $array[(string)$entry->getName()] = [
+                    'content' => $entry->getDisplayValue(),
+                    'visible' => '(' . $entry->getPermsDescription() . ')',
+                ];
+            }
+        }
+
+        return $array;
+    }
+
+    /**
+     * Filter short datafiels from the datafields
+     *
+     * @return array
+     */
+    private function getShortDatafields(): array
+    {
+        $shortDatafields = $this->getDatafields();
+        $array = [];
+
+        if (!empty($shortDatafields)) {
+            foreach ($shortDatafields['short'] as $entry) {
+                $array[(string)$entry->getName()] = [
+                    'content' => $entry->getDisplayValue(),
+                    'visible' => '(' . $entry->getPermsDescription() . ')',
+                ];
+            }
+        }
+        return $array;
+    }
+
+    /**
+     * Creates an array with all seminars
+     *
+     * @return array
+     */
+    private function getTeacherSeminars(): array
+    {
+        $courses = [];
+        $semester = [];
+        $next_semester = Semester::findNext();
+        $current_semester = Semester::findCurrent();
+        $previous_semester = Semester::findPrevious();
+        if ($next_semester) {
+            $semester[$next_semester->id] = $next_semester;
+        }
+        if ($current_semester) {
+            $semester[$current_semester->id] = $current_semester;
+        }
+        if ($previous_semester) {
+            $semester[$previous_semester->id] = $previous_semester;
+        }
+        $field = 'name';
+        if (Config::get()->IMPORTANT_SEMNUMBER) {
+            $field = "veranstaltungsnummer,{$field}";
+        }
+        $allcourses = new SimpleCollection(
+            Course::findBySQL(
+                "INNER JOIN seminar_user USING(Seminar_id) WHERE user_id=? AND seminar_user.status='dozent' AND seminare.visible=1",
+                [
+                    $this->current_user->id
+                ]
+            )
+        );
+        foreach (array_filter($semester) as $one) {
+            $courses[(string) $one->name] = $allcourses->filter(function ($c) use ($one) {
+                if (Config::get()->HIDE_STUDYGROUPS_FROM_PROFILE && $c->isStudygroup()) {
+                    return false;
+                }
+                if (!$c->isOpenEnded()) {
+                    return $c->isInSemester($one);
+                } elseif ($one->isCurrent()) {
+                    return $c;
+                }
+                return false;
+            })->orderBy($field);
+
+            if (!$courses[(string) $one->name]->count()) {
+                unset($courses[(string) $one->name]);
+            }
+        }
+        return $courses;
+    }
+
+    /**
+     * Get the homepagevisibilities
+     *
+     * @return array
+     */
+    private function getHomepageVisibilities(): array
+    {
+        $visibilities = get_local_visibility_by_id(
+            $this->current_user ? $this->current_user->id : null,
+            'homepage'
+        );
+        if (is_array(json_decode($visibilities, true))) {
+            return json_decode($visibilities, true);
+        }
+        return [];
+    }
+
+    /**
+     * Returns the visibility value
+     */
+    private function getVisibilityValue(string $param, string $visibility = ''): mixed
+    {
+        if (Visibility::verify($visibility ?: $param, $this->current_user->user_id)) {
+            return $this->current_user->$param;
+        }
+        return false;
+    }
 }
diff --git a/app/controllers/profilemodules.php b/app/controllers/profilemodules.php
index 201c4ff..c24d4f4 100644
--- a/app/controllers/profilemodules.php
+++ b/app/controllers/profilemodules.php
@@ -106,7 +106,7 @@ class ProfileModulesController extends AuthenticatedController
         $plugins = [];
 
         // Get homepage plugins from database.
-        foreach (PluginEngine::getPlugins('HomepagePlugin') as $plugin) {
+        foreach (PluginEngine::getPlugins(HomepagePlugin::class) as $plugin) {
             if ($plugin->isActivatableForContext($this->user)) {
                 $plugins[$plugin->getPluginId()] = $plugin;
             }
diff --git a/app/controllers/questionnaire.php b/app/controllers/questionnaire.php
index 66a4e0b..94e4d04 100644
--- a/app/controllers/questionnaire.php
+++ b/app/controllers/questionnaire.php
@@ -1,7 +1,5 @@
 <?php
 
-require_once 'lib/classes/QuestionType.interface.php';
-
 class QuestionnaireController extends AuthenticatedController
 {
     protected $allow_nobody = true; //nobody is allowed
@@ -48,11 +46,24 @@ class QuestionnaireController extends AuthenticatedController
     public function courseoverview_action()
     {
         $this->range_id = Context::getId();
+
+        if (!$this->range_id) {
+            throw new CheckObjectException(_('Sie haben kein Objekt gewählt.'));
+        }
         $this->range_type = Context::getType();
         if (!$GLOBALS['perm']->have_studip_perm("tutor", $this->range_id)) {
             throw new AccessDeniedException("Only for logged in users.");
         }
+
         Navigation::activateItem("/course/admin/questionnaires");
+        if ($GLOBALS['perm']->have_studip_perm('admin', $this->range_id)) {
+            // Ensure the select widget is added last
+            NotificationCenter::on('SidebarWillRender', function () {
+                $widget = new CourseManagementSelectWidget();
+                Sidebar::get()->addWidget($widget);
+            });
+        }
+
         $this->statusgruppen = Statusgruppen::findByRange_id($this->range_id);
         $this->questionnaires = Questionnaire::findBySQL(
             "INNER JOIN questionnaire_assignments USING (questionnaire_id) WHERE (questionnaire_assignments.range_id = ? AND questionnaire_assignments.range_type = ?) OR (questionnaire_assignments.range_id IN (?) AND questionnaire_assignments.range_type = 'statusgruppe') ORDER BY questionnaires.chdate DESC",
@@ -148,7 +159,7 @@ class QuestionnaireController extends AuthenticatedController
             : null;
 
         $this->questionnaire['user_id'] = User::findCurrent()->id;
-        $questions_data = Request::getArray('questions_data');
+        $questions_data = json_decode(Request::get('questions_data'), true);
         $questions = [];
         foreach ($questions_data as $index => $question_data) {
             $class = $question_data['questiontype'];
@@ -480,7 +491,7 @@ class QuestionnaireController extends AuthenticatedController
                 $course_assignment['user_id'] = $GLOBALS['user']->id;
                 $course_assignment->store();
             }
-            foreach (PluginManager::getInstance()->getPlugins("QuestionnaireAssignmentPlugin") as $plugin) {
+            foreach (PluginManager::getInstance()->getPlugins(QuestionnaireAssignmentPlugin::class) as $plugin) {
                 $plugin->storeQuestionnaireAssignments($this->questionnaire);
             }
 
@@ -584,8 +595,8 @@ class QuestionnaireController extends AuthenticatedController
         }
         $this->statusgruppen_ids = [];
         if (in_array($this->range_type, ["course", "institute"])) {
-            if ($GLOBALS['perm']->have_studip_perm("tutor", $this->range_id)) {
-                $statusgruppen = Statusgruppen::findByRange_id(Context::get()->id);
+            if ($this->range_id && $GLOBALS['perm']->have_studip_perm("tutor", $this->range_id)) {
+                $statusgruppen = Statusgruppen::findByRange_id($this->range_id);
             } else {
                 $statusgruppen = Statusgruppen::findBySQL("INNER JOIN statusgruppe_user USING (statusgruppe_id) WHERE statusgruppen.range_id = ? AND statusgruppe_user.user_id = ? ", [
                     Context::get()->id,
@@ -634,6 +645,7 @@ class QuestionnaireController extends AuthenticatedController
             object_set_visit($questionnaire['questionnaire_id'], 'vote');
         }
         if (in_array($this->range_type, ["course", "institute"])
+                && $this->range_id
                 && !$GLOBALS['perm']->have_studip_perm("tutor", $this->range_id)
                 && !($stopped_visible || count($this->questionnaire_data))) {
             $this->render_nothing();
diff --git a/app/controllers/quicksearch.php b/app/controllers/quicksearch.php
index 194f317..c086498 100644
--- a/app/controllers/quicksearch.php
+++ b/app/controllers/quicksearch.php
@@ -14,7 +14,7 @@
 
 /**
  * Controller for the ajax-response of the QuickSearch class found in
- * lib/classes/QuickSearch.class.php
+ * lib/classes/QuickSearch.php
  */
 class QuicksearchController extends AuthenticatedController
 {
@@ -94,7 +94,7 @@ class QuicksearchController extends AuthenticatedController
                 if (!empty($result[3])) {
                     $formatted['item_description'] = sprintf('%s (%s)', $result[2], $result[3]);
                 } else {
-                    $formatted['item_description'] = $result[2];
+                    $formatted['item_description'] = $result[2] ?? '';
                 }
             } else if ($this->search instanceof SearchType) {
                  $formatted['item_name'] = $this->search->getAvatarImageTag($result[0], Avatar::SMALL, ['title' => '']) . $formatted['item_name'];
diff --git a/app/controllers/quickselection.php b/app/controllers/quickselection.php
index 1899e53..a53eb08 100644
--- a/app/controllers/quickselection.php
+++ b/app/controllers/quickselection.php
@@ -27,7 +27,7 @@ class QuickselectionController extends AuthenticatedController
 
         UserConfig::get($GLOBALS['user']->id)->store('QUICK_SELECTION', $names);
 
-        $template = PluginEngine::getPlugin('QuickSelection')->getPortalTemplate();
+        $template = PluginEngine::getPlugin(QuickSelection::class)->getPortalTemplate();
 
         $this->response->add_header('X-Dialog-Close', 1);
         $this->response->add_header('X-Dialog-Execute', 'STUDIP.QuickSelection.update');
diff --git a/app/controllers/resources/ajax.php b/app/controllers/resources/ajax.php
index 6ff3942..cffd878 100644
--- a/app/controllers/resources/ajax.php
+++ b/app/controllers/resources/ajax.php
@@ -16,22 +16,22 @@ class Resources_AjaxController extends AuthenticatedController
 {
     public function toggle_marked_action($request_id)
     {
-        $request = \ResourceRequest::find($request_id);
+        $request = ResourceRequest::find($request_id);
 
         if (!$request) {
             throw new Exception('Resource request object not found!');
         }
 
-        $current_user = \User::findCurrent();
+        $current_user = User::findCurrent();
 
         if ($request->isReadOnlyForUser($current_user)) {
-            throw new \AccessDeniedException();
+            throw new AccessDeniedException();
         }
 
         //Switch to the next marking state or return to the unmarked state
         //if the next marking state would be after the last defined
         //marking state.
-        $request->marked = ($request->marked + 1) % \ResourceRequest::MARKING_STATES;
+        $request->marked = ($request->marked + 1) % ResourceRequest::MARKING_STATES;
         $request->store();
 
         $this->render_json($request->toArray());
@@ -39,46 +39,46 @@ class Resources_AjaxController extends AuthenticatedController
 
     public function get_resource_booking_intervals_action($booking_id)
     {
-        $booking = \ResourceBooking::find($booking_id);
+        $booking = ResourceBooking::find($booking_id);
         if (!$booking) {
             throw new Exception('Resource booking object not found!');
         }
 
         $resource = $booking->resource->getDerivedClassInstance();
-        if (!$resource->bookingPlanVisibleForUser(\User::findCurrent())) {
-            throw new \AccessDeniedException();
+        if (!$resource->bookingPlanVisibleForUser(User::findCurrent())) {
+            throw new AccessDeniedException();
         }
 
         //Get begin and end:
-        $begin_str = \Request::get('begin');
-        $end_str   = \Request::get('end');
+        $begin_str = Request::get('begin');
+        $end_str   = Request::get('end');
         $begin     = null;
         $end       = null;
         if ($begin_str && $end_str) {
             //Try the ISO format first: YYYY-MM-DDTHH:MM:SS±ZZ:ZZ
-            $begin = \DateTime::createFromFormat(\DateTime::RFC3339, $begin_str);
-            $end   = \DateTime::createFromFormat(\DateTime::RFC3339, $end_str);
-            if (!($begin instanceof \DateTime) || !($end instanceof \DateTime)) {
-                $tz = new \DateTime();
+            $begin = DateTime::createFromFormat(DateTime::RFC3339, $begin_str);
+            $end   = DateTime::createFromFormat(DateTime::RFC3339, $end_str);
+            if (!($begin instanceof DateTime) || !($end instanceof DateTime)) {
+                $tz = new DateTime();
                 $tz = $tz->getTimezone();
                 //Try the ISO format without timezone:
-                $begin = \DateTime::createFromFormat('Y-m-d\TH:i:s', $begin_str, $tz);
-                $end   = \DateTime::createFromFormat('Y-m-d\TH:i:s', $end_str, $tz);
+                $begin = DateTime::createFromFormat('Y-m-d\TH:i:s', $begin_str, $tz);
+                $end   = DateTime::createFromFormat('Y-m-d\TH:i:s', $end_str, $tz);
             }
         }
 
         $sql      = "booking_id = :booking_id ";
         $sql_data = ['booking_id' => $booking->id];
-        if ($begin instanceof \DateTime && $end instanceof \DateTime) {
+        if ($begin instanceof DateTime && $end instanceof DateTime) {
             $sql               .= "AND begin >= :begin AND end <= :end ";
             $sql_data['begin'] = $begin->getTimestamp();
             $sql_data['end']   = $end->getTimestamp();
         }
-        if (\Request::submitted('exclude_cancelled_intervals')) {
+        if (Request::submitted('exclude_cancelled_intervals')) {
             $sql .= "AND takes_place = '1' ";
         }
         $sql       .= "ORDER BY begin ASC, end ASC";
-        $intervals = \ResourceBookingInterval::findBySql($sql, $sql_data);
+        $intervals = ResourceBookingInterval::findBySql($sql, $sql_data);
 
         $result = [];
         foreach ($intervals as $interval) {
@@ -90,7 +90,7 @@ class Resources_AjaxController extends AuthenticatedController
 
     public function toggle_takes_place_field_action($interval_id)
     {
-        $interval = \ResourceBookingInterval::find($interval_id);
+        $interval = ResourceBookingInterval::find($interval_id);
         if (!$interval) {
             throw new Exception('ResourceBookingInterval object not found!');
         }
@@ -103,13 +103,13 @@ class Resources_AjaxController extends AuthenticatedController
 
         $resource = $resource->getDerivedClassInstance();
 
-        if (!$resource->userHasPermission(\User::findCurrent(), 'autor', [$interval->begin, $interval->end])) {
+        if (!$resource->userHasPermission(User::findCurrent(), 'autor', [$interval->begin, $interval->end])) {
             throw new Exception('You do not have sufficient permissions to modify the interval!');
         }
 
         if (
             !$interval->takes_place
-            && $resource->isAssigned(new \DateTime('@' . $interval->begin), new \DateTime('@' . $interval->end))
+            && $resource->isAssigned(new DateTime('@' . $interval->begin), new DateTime('@' . $interval->end))
         ) {
             throw new Exception('Already booked');
         }
@@ -121,13 +121,14 @@ class Resources_AjaxController extends AuthenticatedController
                 'takes_place' => $interval->takes_place
             ]);
         } else {
-            throw new Exception('Error while storing the interval!');
+            $this->set_status(500);
+            $this->render_text('Error while storing the interval!');
         }
     }
 
     public function get_semester_booking_plan_action($resource_id)
     {
-        $resource = \Resource::find($resource_id);
+        $resource = Resource::find($resource_id);
         if (!$resource) {
             throw new Exception('Resource object not found!');
         }
@@ -143,8 +144,8 @@ class Resources_AjaxController extends AuthenticatedController
         $display_requests     = Request::get('display_requests');
         $display_all_requests = Request::get('display_all_requests');
 
-        $begin = new \DateTime();
-        $end   = new \DateTime();
+        $begin = new DateTime();
+        $end   = new DateTime();
 
         $semester_id = Request::get('semester_id');
 
@@ -190,11 +191,11 @@ class Resources_AjaxController extends AuthenticatedController
                 'resource_id' => $resource->id
             ];
             if (!$display_all_requests) {
-                $requests_sql .= "AND user_id = :user_id ";
+                $requests_sql .= " AND user_id = :user_id ";
                 $requests_sql_params['user_id'] = $current_user->id;
             }
 
-            $requests = \ResourceRequest::findBySql(
+            $requests = ResourceRequest::findBySql(
                 $requests_sql,
                 $requests_sql_params
             );
@@ -207,7 +208,7 @@ class Resources_AjaxController extends AuthenticatedController
             $booking->resource  = $resource;
             $irrelevant_booking = $booking->getRepetitionType() !== 'weekly'
                                   && (
-                                      !\Request::get('display_single_bookings')
+                                      !Request::get('display_single_bookings')
                                       || $booking->end < strtotime('today')
                                   );
             if ($booking->getAssignedUserType() === 'course' && in_array($booking->assigned_course_date->metadate_id, $meta_dates)) {
@@ -261,7 +262,7 @@ class Resources_AjaxController extends AuthenticatedController
 
         $relevant_request = false;
         foreach ($requests as $request) {
-            if ($request->cycle instanceof \SeminarCycleDate) {
+            if ($request->cycle instanceof SeminarCycleDate) {
                 $cycle_dates = $request->cycle->getAllDates();
                 foreach ($cycle_dates as $cycle_date) {
                     $relevant_request = $semester->beginn <= $cycle_date->date
@@ -488,7 +489,7 @@ class Resources_AjaxController extends AuthenticatedController
         $clipboard = Clipboard::find($clipboard_id);
 
         if (!empty($_SESSION['selected_clipboard_id'])) {
-            $clipboard = \Clipboard::find($_SESSION['selected_clipboard_id']);
+            $clipboard = Clipboard::find($_SESSION['selected_clipboard_id']);
         }
         if (!$clipboard) {
             throw new Exception('Clipboard object not found!');
@@ -497,7 +498,7 @@ class Resources_AjaxController extends AuthenticatedController
 
         //Permission check:
         if ($clipboard->user_id !== $current_user->id) {
-            throw new \AccessDeniedException();
+            throw new AccessDeniedException();
         }
 
         $display_requests     = Request::bool('display_requests');
@@ -656,4 +657,186 @@ class Resources_AjaxController extends AuthenticatedController
 
         $this->render_json($data);
     }
+
+    public function move_booking_action($booking_id): void
+    {
+        $booking = ResourceBooking::find($booking_id);
+        if (!$booking) {
+            $this->notFound('Resource booking object not found!');
+            return;
+        }
+
+        $current_user = User::findCurrent();
+
+        if ($booking->isReadOnlyForUser($current_user)) {
+            throw new AccessDeniedException();
+        }
+
+        $resource_id = Request::get('resource_id');
+        $interval_id = Request::get('interval_id');
+
+        $begin = $this->convertDatetime(Request::get('begin'));
+        $end = $this->convertDatetime(Request::get('end'));
+
+        //Check if a specific interval has been moved:
+        if ($interval_id) {
+            $interval = ResourceBookingInterval::findOneBySql(
+                'interval_id = ? AND booking_id = ?',
+                [$interval_id, $booking->id]
+            );
+            if (!$interval) {
+                $this->notFound('Resource booking interval not found!');
+                return;
+            }
+            $interval_begin = new DateTime();
+            $interval_begin->setTimestamp($interval->begin);
+            $interval_end = new DateTime();
+            $interval_end->setTimestamp($interval->end);
+
+            //Calculate the difference from the interval time range
+            //to the time range from the request. That difference
+            //is then applied to the booking.
+            $begin_diff = $interval_begin->diff($begin);
+            $end_diff = $interval_end->diff($end);
+
+            $new_booking_begin = new DateTime();
+            $new_booking_begin->setTimestamp($booking->begin);
+            $new_booking_end = new DateTime();
+            $new_booking_end->setTimestamp($booking->end);
+
+            $new_booking_begin = $new_booking_begin->add($begin_diff);
+            $new_booking_end = $new_booking_end->add($end_diff);
+            //We must substract the preparation time to the begin timestamp
+            //to get the real begin:
+            $real_begin = clone $new_booking_begin;
+            if ($booking->preparation_time > 0) {
+                $real_begin->sub(new DateInterval('PT' . ($booking->preparation_time / 60 ) . 'M'));
+            }
+            $booking->begin = $real_begin->getTimestamp();
+            $booking->end = $new_booking_end->getTimestamp();
+        } else {
+            //We must substract the preparation time to the begin timestamp
+            //to get the real begin:
+            $real_begin = clone $begin;
+            if ($booking->preparation_time > 0) {
+                $real_begin->sub(new DateInterval('PT' . ($booking->preparation_time / 60 ) . 'M'));
+            }
+            $booking->begin = $real_begin->getTimestamp();
+            $booking->end = $end->getTimestamp();
+        }
+        if ($resource_id) {
+            //The resource-ID has changed:
+            //The booking was moved from one resource to another.
+            $booking->resource_id = $resource_id;
+        }
+
+        //Update the booking_user_id field:
+        $booking->booking_user_id = User::findCurrent()->id;
+
+        try {
+            $booking->store();
+
+            if (Request::bool('quiet')) {
+                $this->render_nothing();
+            } else {
+                $this->render_json($booking->toRawArray());
+            }
+        } catch (Exception $e) {
+            $this->set_status(500);
+            $this->render_text($e->getMessage());
+        }
+    }
+
+    public function move_request_action($request_id): void
+    {
+        $request = ResourceRequest::find($request_id);
+        if (!$request) {
+            $this->notFound('Resource request object not found!');
+            return;
+        }
+
+        $current_user = User::findCurrent();
+
+        if ($request->isReadOnlyForUser($current_user)) {
+            throw new AccessDeniedException();
+        }
+
+        $request->begin = $this->convertDatetime(Request::get('begin'));
+        $request->end = $this->convertDatetime(Request::get('end'));
+
+        try {
+            $request->store();
+            $this->renderObject($request);
+        } catch (\Exception $e) {
+            $this->set_status(500);
+            $this->render_text($e->getMessage());
+        }
+    }
+
+    public function semester_week_action($timestamp)
+    {
+        $semester = \Semester::findByTimestamp($timestamp);
+        if (!$semester) {
+            $this->notFound('No semester found for given timestamp');
+            throw new RecordNotFoundException();
+        }
+
+        $timestamp = strtotime('today', $timestamp);
+        $week_begin_timestamp = strtotime('monday this week', $semester->vorles_beginn);
+        $end_date = $semester->vorles_ende;
+
+        $i = 0;
+        $result = [
+            'semester_name' => (string)$semester->name,
+            'week_number' => sprintf(_('KW %u'), date('W', $timestamp)),
+            'current_day' => strftime('%x', $timestamp)
+        ];
+        while ($week_begin_timestamp < $end_date) {
+            $next_week_timestamp = strtotime('+1 week', $week_begin_timestamp);
+            if ($week_begin_timestamp <= $timestamp && $timestamp < $next_week_timestamp) {
+                $result['sem_week'] = sprintf(
+                    _('%u. Vorlesungswoche (ab %s)'),
+                    $i + 1,
+                    strftime('%x', $week_begin_timestamp));
+                break;
+            }
+            $i += 1;
+
+            $week_begin_timestamp = $next_week_timestamp;
+        }
+
+        $this->render_json($result);
+    }
+
+    private function notFound(string $message = ''): void
+    {
+        $this->set_status(404);
+        $this->render_text($message);
+    }
+
+    private function renderObject(SimpleORMap $object): void
+    {
+        if (Request::bool('quiet')) {
+            $this->render_nothing();
+        } else{
+            $this->render_json($object->toArray());
+        }
+    }
+
+    /**
+     * Tries the ISO format first: YYYY-MM-DDTHH:MM:SS±ZZ:ZZ
+     */
+    private function convertDatetime(?string $input): ?Datetime
+    {
+        if (!$input) {
+            return null;
+        }
+
+        return DateTime::createFromFormat(DateTime::RFC3339, $input)
+            ?? DateTime::createFromFormat(
+                   'Y-m-d\TH:i:s',
+                   $input,
+                   (new DateTime())->getTimezone()
+               );
+    }
 }
diff --git a/app/controllers/resources/booking.php b/app/controllers/resources/booking.php
index 294aeaa..a4722ed 100644
--- a/app/controllers/resources/booking.php
+++ b/app/controllers/resources/booking.php
@@ -242,9 +242,7 @@ class Resources_BookingController extends AuthenticatedController
             return true;
         }
 
-        $template_factory = new Flexi_TemplateFactory(
-            $GLOBALS['STUDIP_BASE_PATH'] . '/locale/'
-        );
+        $template_factory = new Flexi\Factory($GLOBALS['STUDIP_BASE_PATH'] . '/locale/');
 
         $derived_resource = $booking->resource->getDerivedClassInstance();
         $system_lang = $_SESSION['_language'];
@@ -1354,7 +1352,7 @@ class Resources_BookingController extends AuthenticatedController
                     $resource,
                     $time_intervals,
                     [1, 3],
-                    ($this->booking->id ? [$this->booking->id] : [])
+                    isset($this->booking->id) ? [$this->booking->id] : []
                 );
                 $reservations_to_overwrite = array_merge(
                     $reservations_to_overwrite,
diff --git a/app/controllers/resources/room_request.php b/app/controllers/resources/room_request.php
index 6421f23..4c51beb 100644
--- a/app/controllers/resources/room_request.php
+++ b/app/controllers/resources/room_request.php
@@ -1739,8 +1739,8 @@ class Resources_RoomRequestController extends AuthenticatedController
         if ($save_only) {
             // redirect to reload all infos and showing the most current ones
             $this->redirect('resources/room_request/resolve/' . $request_id);
-        } elseif (Request::isDialog() && Context::get()) {
-            $this->response->add_header('X-Dialog-Execute', '{"func": "STUDIP.AdminCourses.App.loadCourse", "payload": "'.Context::get()->id.'"}');
+        } elseif (Request::isDialog() && Context::get()->id) {
+            $this->response->add_header('X-Dialog-Execute', '{"func": "STUDIP.AdminCourses.App.loadCourse", "payload": "' . Context::get()->id . '"}');
         }
     }
 
diff --git a/app/controllers/room_management/planning.php b/app/controllers/room_management/planning.php
index c450c64..3da7904 100644
--- a/app/controllers/room_management/planning.php
+++ b/app/controllers/room_management/planning.php
@@ -38,7 +38,7 @@ class RoomManagement_PlanningController extends AuthenticatedController
         if ($selected_clipboard_id) {
             $_SESSION['selected_clipboard_id'] = $selected_clipboard_id;
         } else {
-            $selected_clipboard_id = $_SESSION['selected_clipboard_id'];
+            $selected_clipboard_id = $_SESSION['selected_clipboard_id'] ?? null;
         }
 
         $this->display_all_requests = Request::get('display_all_requests');
@@ -282,7 +282,7 @@ class RoomManagement_PlanningController extends AuthenticatedController
         if ($selected_clipboard_id) {
             $_SESSION['selected_clipboard_id'] = $selected_clipboard_id;
         } else {
-            $selected_clipboard_id = $_SESSION['selected_clipboard_id'];
+            $selected_clipboard_id = $_SESSION['selected_clipboard_id'] ?? null;
         }
 
         $this->display_all_requests = Request::get('display_all_requests');
@@ -411,7 +411,7 @@ class RoomManagement_PlanningController extends AuthenticatedController
         }
 
         //Check if a clipboard is selected:
-        $selected_clipboard_id = $_SESSION['selected_clipboard_id'];
+        $selected_clipboard_id = $_SESSION['selected_clipboard_id'] ?? null;
         $rooms = [];
         if ($selected_clipboard_id) {
             $clipboard = Clipboard::find($selected_clipboard_id);
@@ -1075,7 +1075,7 @@ class RoomManagement_PlanningController extends AuthenticatedController
         if ($selected_clipboard_id) {
             $_SESSION['selected_clipboard_id'] = $selected_clipboard_id;
         } else {
-            $selected_clipboard_id = $_SESSION['selected_clipboard_id'];
+            $selected_clipboard_id = $_SESSION['selected_clipboard_id'] ?? null;
         }
 
         //Get the selected date or use the current date, if none specified:
@@ -1371,7 +1371,7 @@ class RoomManagement_PlanningController extends AuthenticatedController
         $export = Request::get('export');
         if ($export == 'html') {
             //Load the export template:
-            $factory = new Flexi_TemplateFactory(
+            $factory = new Flexi\Factory(
                 $GLOBALS['STUDIP_BASE_PATH'] . '/app/views/room_management/planning/'
             );
 
diff --git a/app/controllers/search/courses.php b/app/controllers/search/courses.php
index 6ae9d6a..a6a4d27 100644
--- a/app/controllers/search/courses.php
+++ b/app/controllers/search/courses.php
@@ -40,6 +40,7 @@ class Search_CoursesController extends AuthenticatedController
     public function index_action()
     {
         $nodeClass = '';
+        $title = _('Vorlesungsverzeichnis');
         if (Request::option('type', 'semtree') === 'semtree') {
             Navigation::activateItem('/search/courses/semtree');
             $nodeClass = StudipStudyArea::class;
@@ -52,22 +53,12 @@ class Search_CoursesController extends AuthenticatedController
             $this->treeTitle = _('Einrichtungen');
             $this->breadcrumbIcon = 'institute';
             $this->editUrl = $this->url_for('rangetree/edit');
+            $title = _('Einrichtungsverzeichnis');
         }
         $this->startId = Request::option('node_id', $nodeClass . '_root');
 
         $this->setupSidebar();
-    }
-
-    public function export_results_action()
-    {
-        $sem_browse_obj = new SemBrowse();
-        $tmpfile = basename($sem_browse_obj->create_result_xls());
-        if ($tmpfile) {
-            $this->redirect(FileManager::getDownloadURLForTemporaryFile(
-                    $tmpfile, _('ErgebnisVeranstaltungssuche.xls'), 4));
-        } else {
-            $this->render_nothing();
-        }
+        PageLayout::setTitle($title);
     }
 
     private function setupSidebar()
@@ -110,17 +101,7 @@ class Search_CoursesController extends AuthenticatedController
         }
 
         $sidebar->addWidget(new VueWidget('search-widget'));
+        $sidebar->addWidget(new VueWidget('views-widget'));
         $sidebar->addWidget(new VueWidget('export-widget'));
-
-        $views = new ViewsWidget();
-        $views->addLink(
-            _('Als Liste'),
-            $this->url_for('search/courses', array_merge($params, ['show_as' => 'list']))
-        )->setActive($this->show_as === 'list');
-        $views->addLink(
-            _('Als Tabelle'),
-            $this->url_for('search/courses', array_merge($params, ['show_as' => 'table']))
-        )->setActive($this->show_as === 'table');
-        $sidebar->addWidget($views);
     }
 }
diff --git a/app/controllers/search/globalsearch.php b/app/controllers/search/globalsearch.php
index ed4ed6e..05fcda2 100644
--- a/app/controllers/search/globalsearch.php
+++ b/app/controllers/search/globalsearch.php
@@ -72,37 +72,40 @@ class Search_GlobalsearchController extends AuthenticatedController
             }
         }
 
-        $semester_filter = $sidebar->addWidget(new OptionsWidget(_('Semester')));
-        $semester_filter->id = 'semester_filter';
-        $semester_filter->addSelect(
-            _('Semester'),
-            null,
-            'semester',
-            $this->getSemesters(),
-            'future',
-            ['id' => 'semester_select']
+        $filter_widget = $sidebar->addWidget(new OptionsWidget(_('Filter')));
+        $filter_widget->id = 'filter_widget';
+
+        $filter_widget->addElement(
+            new SelectListElement(
+                _('Semester'),
+                'semester',
+                $this->getSemesters(),
+                'future',
+                ['id' => 'semester_select']
+            ),
+            'semester_filter'
         );
 
-        $seminar_type_filter = $sidebar->addWidget(new OptionsWidget(_('Veranstaltungstypen')));
-        $seminar_type_filter->id = 'seminar_type_filter';
-        $seminar_type_filter->addSelect(
-            _('Typ der Veranstaltung'),
-            null,
-            'seminar_type',
-            $this->getSemClasses(),
-            '',
-            ['id' => 'seminar_type_select']
+        $filter_widget->addElement(
+            new SelectListElement(
+                _('Typ der Veranstaltung'),
+                'seminar_type',
+                $this->getSemClasses(),
+                '',
+                ['id' => 'seminar_type_select']
+            ),
+            'seminar_type_filter'
         );
 
-        $institute_filter = $sidebar->addWidget(new OptionsWidget(_('Einrichtungen')));
-        $institute_filter->id = 'institute_filter';
-        $institute_filter->addSelect(
-            _('Einrichtung'),
-            null,
-            'institute',
-            $this->getInstitutes(),
-            '',
-            ['id' => 'institute_select']
+        $filter_widget->addElement(
+            new SelectListElement(
+                _('Einrichtung'),
+                'institute',
+                $this->getInstitutes(),
+                '',
+                ['id' => 'institute_select']
+            ),
+            'institute_filter'
         );
     }
 
diff --git a/app/controllers/search/studiengaenge.php b/app/controllers/search/studiengaenge.php
index a075ce9..e17eb2a 100644
--- a/app/controllers/search/studiengaenge.php
+++ b/app/controllers/search/studiengaenge.php
@@ -228,7 +228,7 @@ class Search_StudiengaengeController extends MVVController
             } else {
                 $this->active_sem = Semester::find($this->sessGet('selected_semester', Semester::findCurrent()->id));
             }
-            $this->active_sem = $this->semesters[$this->active_sem->id] ? $this->active_sem : null;
+            $this->active_sem = !empty($this->semesters[$this->active_sem->id]) ? $this->active_sem : null;
             if (!$this->active_sem && count($this->semesters)) {
                 $active_sem = reset($this->semesters);
                 $this->active_sem = Semester::find($active_sem['semester_id']);
@@ -423,7 +423,7 @@ class Search_StudiengaengeController extends MVVController
     {
         $this->abschnitt = StgteilAbschnitt::find($abschnitt_id);
         if (!$this->abschnitt) {
-            throw new Trails_Exception(404);
+            throw new Trails\Exception(404);
         }
         $this->render_template('search/studiengaenge/kommentar', $this->layout);
     }
diff --git a/app/controllers/settings/general.php b/app/controllers/settings/general.php
index 734cca1..0e8ec70 100644
--- a/app/controllers/settings/general.php
+++ b/app/controllers/settings/general.php
@@ -44,6 +44,7 @@ class Settings_GeneralController extends Settings_SettingsController
     public function index_action()
     {
         $this->user_language = getUserLanguage($this->user->id);
+        $this->notifications_placement = User::findCurrent()->getConfiguration()->SYSTEM_NOTIFICATIONS_PLACEMENT;
     }
 
     /**
@@ -80,6 +81,7 @@ class Settings_GeneralController extends Settings_SettingsController
         } else {
             PersonalNotifications::deactivateAudioFeedback($this->user->id);
         }
+        $this->config->store('SYSTEM_NOTIFICATIONS_PLACEMENT', Request::get('system_notifications_placement'));
 
         PageLayout::postSuccess(_('Die Einstellungen wurden gespeichert.'));
         $this->redirect('settings/general');
diff --git a/app/controllers/settings/settings.php b/app/controllers/settings/settings.php
index 0346c24..9cd00c0 100644
--- a/app/controllers/settings/settings.php
+++ b/app/controllers/settings/settings.php
@@ -46,11 +46,11 @@ abstract class Settings_SettingsController extends AuthenticatedController
             $exception = new AccessDeniedException(_('Sie dürfen dieses Profil nicht bearbeiten'));
             $exception->setDetails([
                 _("Wahrscheinlich ist Ihre Session abgelaufen. Bitte "
-                 ."nutzen Sie in diesem Fall den untenstehenden Link, "
+                 ."nutzen Sie in diesem Fall den folgenden Link, "
                  ."um zurück zur Anmeldung zu gelangen.\n\n"
                  ."Eine andere Ursache kann der Versuch des Zugriffs "
                  ."auf Userdaten, die Sie nicht bearbeiten dürfen, sein. "
-                 ."Nutzen Sie den untenstehenden Link, um zurück auf "
+                 ."Nutzen Sie den folgenden Link, um zurück auf "
                  ."die Startseite zu gelangen."),
             ]);
             throw $exception;
@@ -121,7 +121,7 @@ abstract class Settings_SettingsController extends AuthenticatedController
     public function get_default_template($action)
     {
         $class = get_class($this);
-        $controller_name = Trails_Inflector::underscore(mb_substr($class, 0, -10));
+        $controller_name = Trails\Inflector::underscore(mb_substr($class, 0, -10));
         return file_exists($this->dispatcher->trails_root . '/views/' . $controller_name . '.php')
             ? $controller_name
             : $controller_name . '/' . $action;
diff --git a/app/controllers/shared/contacts.php b/app/controllers/shared/contacts.php
index 98670f4..820d2ab 100644
--- a/app/controllers/shared/contacts.php
+++ b/app/controllers/shared/contacts.php
@@ -114,7 +114,7 @@ class Shared_ContactsController extends MVVController
         if ($this->contact_id) {
             $contact_range = MvvContactRange::findOneBySQL('contact_id=?', [$this->contact_id]);
             if (!$contact_range) {
-                throw new Trails_Exception(404);
+                throw new Trails\Exception(404);
             }
             $this->relations = $contact_range->getRelations($this->filter);
             $this->origin = 'index';
@@ -155,7 +155,7 @@ class Shared_ContactsController extends MVVController
     {
         $this->contact_range = MvvContactRange::findOneBySQL('contact_id = ?', [$contact_id]);
         if (!$this->contact_range) {
-            throw new Trails_Exception(404);
+            throw new Trails\Exception(404);
         }
 
         $this->relations = $this->contact_range->getRelations($this->filter);
@@ -725,7 +725,7 @@ class Shared_ContactsController extends MVVController
         $this->mvvcontact_id = $user_id;
 
         $this->selected_sem_end = $this->filter['end_sem.ende'];
-        $this->selected_inst = $this->filter['mvv_studiengang.institut_id'];
+        $this->selected_inst = $this->filter['mvv_studiengang.institut_id'] ?? null;
 
         if (Request::submitted('store')) {
             $selected = Request::getArray('ranges');
@@ -871,7 +871,7 @@ class Shared_ContactsController extends MVVController
         ));
         $filter = [
             'mvv_modul.stat'             => $stat,
-            'mvv_modul_inst.institut_id' => $this->filter['mvv_modul_inst.institut_id'],
+            'mvv_modul_inst.institut_id' => $this->filter['mvv_modul_inst.institut_id'] ?? '',
             'start_sem.beginn'           => $this->filter['start_sem.beginn'],
             'end_sem.ende'               => $this->filter['end_sem.ende']
         ];
diff --git a/app/controllers/shared/download.php b/app/controllers/shared/download.php
index 92d15d9..f94bc86 100644
--- a/app/controllers/shared/download.php
+++ b/app/controllers/shared/download.php
@@ -158,7 +158,7 @@ class Shared_DownloadController extends AuthenticatedController
         }
 
         $path = $GLOBALS['STUDIP_BASE_PATH'] . '/app/views/shared/modul/';
-        $factory = new Flexi_TemplateFactory($path);
+        $factory = new Flexi\Factory($path);
 
         $template = $factory->open('_modul');
         $template->_ = function ($string) { return $this->_($string); };
@@ -166,7 +166,7 @@ class Shared_DownloadController extends AuthenticatedController
         $template->display_language = $display_language;
         $content = $template->render();
 
-        $factory = new \Flexi_TemplateFactory($path);
+        $factory = new Flexi\Factory($path);
         $type = 1;
         if (count($modul->modulteile) == 1) {
             $modulteil = $modul->modulteile->first();
diff --git a/app/controllers/shared/log_event.php b/app/controllers/shared/log_event.php
index 0355e45..3d8af7e 100644
--- a/app/controllers/shared/log_event.php
+++ b/app/controllers/shared/log_event.php
@@ -122,12 +122,12 @@ class Shared_LogEventController extends MVVController
                     $search_action .= " AND `log_actions`.`name` LIKE CONCAT('%_'," . DBManager::get()->quote($log_action) . ")";
                 }
 
-                $statement = DBManager::get()->prepare("SELECT *, `log_actions`.`name`
+                $statement = DBManager::get()->prepare("SELECT *
                         FROM `log_events`
                         LEFT JOIN `log_actions` ON `log_events`.`action_id` =  `log_actions`.`action_id`
                         WHERE `info` = ?
                         " . $search_action . "
-                        ORDER BY `log_events`.`mkdate` DESC");
+                        ORDER BY `log_events`.`event_id` DESC");
                 $statement->execute([$mvv_field]);
                 $res = $statement->fetchOne();
                 if ($res) {
diff --git a/app/controllers/siteinfo.php b/app/controllers/siteinfo.php
index ab81660..7bc95cb 100644
--- a/app/controllers/siteinfo.php
+++ b/app/controllers/siteinfo.php
@@ -37,7 +37,7 @@ class SiteinfoController extends StudipController
         } else {
             $action = 'show';
             if ($this->page_is_draft || ($this->page_disabled_nobody && $GLOBALS['user']->id === 'nobody')) {
-                throw new Trails_Exception(404);
+                throw new Trails\Exception(404);
             }
         }
         $this->add_navigation($action);
diff --git a/app/controllers/start.php b/app/controllers/start.php
index 53a87dc..8231095 100644
--- a/app/controllers/start.php
+++ b/app/controllers/start.php
@@ -53,10 +53,13 @@ class StartController extends AuthenticatedController
             }
         }
 
+        $this->widget_layout = $this->get_template_factory()->open('start/_widget.php');
+
         $sidebar = Sidebar::get();
 
         $nav = $sidebar->addWidget(new NavigationWidget());
         $nav->setTitle(_('Sprungmarken'));
+        $nav->setId('navigation-layer-3');
         foreach (array_merge(...$this->columns) as $widget) {
             $nav->addLink(
                 $widget->getPluginName(),
@@ -132,7 +135,7 @@ class StartController extends AuthenticatedController
      */
     private function getAvailableWidgets($user_id)
     {
-        $all_widgets = PluginEngine::getPlugins('PortalPlugin');
+        $all_widgets = PluginEngine::getPlugins(PortalPlugin::class);
         $user_widgets = WidgetUser::getWidgets($user_id);
         $used_widgets = array_merge(...$user_widgets);
         $available = [];
@@ -190,7 +193,7 @@ class StartController extends AuthenticatedController
 
         PageLayout::setTitle(sprintf(_('Standard-Startseite für "%s" bearbeiten'), ucfirst($permission)));
 
-        $this->widgets = PluginEngine::getPlugins('PortalPlugin');
+        $this->widgets = PluginEngine::getPlugins(PortalPlugin::class);
         $this->initial_widgets = WidgetDefault::getWidgets($permission);
         $this->permission = $permission;
     }
diff --git a/app/controllers/studiengaenge/abschluesse.php b/app/controllers/studiengaenge/abschluesse.php
index 8ec055b..60bc091 100644
--- a/app/controllers/studiengaenge/abschluesse.php
+++ b/app/controllers/studiengaenge/abschluesse.php
@@ -50,7 +50,7 @@ class Studiengaenge_AbschluesseController extends Studiengaenge_StudiengaengeCon
         $perm_institutes = MvvPerm::getOwnInstitutes();
         $abschluss = Abschluss::find($abschluss_id);
         if (!$abschluss) {
-            throw new Trails_Exception(404);
+            throw new Trails\Exception(404);
         }
         $this->abschluss_id = $abschluss->id;
         if (count($perm_institutes)) {
@@ -59,7 +59,7 @@ class Studiengaenge_AbschluesseController extends Studiengaenge_StudiengaengeCon
                 $perm_institutes
             );
             if (!count($institutes_abschluss)) {
-                throw new Trails_Exception(403);
+                throw new Trails\Exception(403);
             }
             $this->studiengaenge = SimpleORMapCollection::createFromArray(
                 Studiengang::findByAbschluss_id($this->abschluss_id)
@@ -91,4 +91,4 @@ class Studiengaenge_AbschluesseController extends Studiengaenge_StudiengaengeCon
             $this->perform_relayed('index');
         }
     }
-}
\ No newline at end of file
+}
diff --git a/app/controllers/studiengaenge/fachbereiche.php b/app/controllers/studiengaenge/fachbereiche.php
index 970c8d9..35f997b 100644
--- a/app/controllers/studiengaenge/fachbereiche.php
+++ b/app/controllers/studiengaenge/fachbereiche.php
@@ -51,7 +51,7 @@ class Studiengaenge_FachbereicheController extends Studiengaenge_StudiengaengeCo
         $this->fachbereich_id = $fachbereich_id;
         if (count($perm_institutes)) {
             if (!in_array($this->fachbereich_id, $perm_institutes)) {
-                throw new Trails_Exception(403);
+                throw new Trails\Exception(403);
             }
         }
 
diff --git a/app/controllers/studiengaenge/fachbereichestgteile.php b/app/controllers/studiengaenge/fachbereichestgteile.php
index c8037dc..73ad2aa 100644
--- a/app/controllers/studiengaenge/fachbereichestgteile.php
+++ b/app/controllers/studiengaenge/fachbereichestgteile.php
@@ -67,7 +67,7 @@ class Studiengaenge_FachbereichestgteileController extends Studiengaenge_Studien
             $this->fachbereich = $fachbereich;
             $this->perform_relayed('stgteil');
         } else {
-            throw new Trails_Exception(404);
+            throw new Trails\Exception(404);
         }
     }
 }
diff --git a/app/controllers/studiengaenge/faecher.php b/app/controllers/studiengaenge/faecher.php
index c9546a3..9990f7d 100644
--- a/app/controllers/studiengaenge/faecher.php
+++ b/app/controllers/studiengaenge/faecher.php
@@ -83,7 +83,7 @@ class Studiengaenge_FaecherController extends Studiengaenge_StudiengangteileCont
             $this->stgteil = StudiengangTeil::get();
             $this->stgteil->assignFach($fach->getId());
         } else {
-            throw new Trails_Exception(404);
+            throw new Trails\Exception(404);
         }
         $this->perform_relayed('stgteil');
     }
diff --git a/app/controllers/studiengaenge/kategorien.php b/app/controllers/studiengaenge/kategorien.php
index 03d28fc..8f6a98d 100644
--- a/app/controllers/studiengaenge/kategorien.php
+++ b/app/controllers/studiengaenge/kategorien.php
@@ -73,7 +73,7 @@ class Studiengaenge_KategorienController extends Studiengaenge_StudiengaengeCont
             
             if (count($perm_institutes)) {
                 if (!in_array($studiengang->institut_id, $perm_institutes)) {
-                    throw new Trails_Exception(403);
+                    throw new Trails\Exception(403);
                 }
             }
             
@@ -98,4 +98,4 @@ class Studiengaenge_KategorienController extends Studiengaenge_StudiengaengeCont
             $this->perform_relayed('index');
         }
     }
-}
\ No newline at end of file
+}
diff --git a/app/controllers/studiengaenge/shared_version.php b/app/controllers/studiengaenge/shared_version.php
index 696fac0..a6265b0 100644
--- a/app/controllers/studiengaenge/shared_version.php
+++ b/app/controllers/studiengaenge/shared_version.php
@@ -11,18 +11,18 @@ abstract class SharedVersionController extends MVVController
     {
         $this->stgteil = StudiengangTeil::find($stgteil_id);
         if (!$this->stgteil) {
-            throw new Trails_Exception(404);
+            throw new Trails\Exception(404);
         }
 
         if (!MvvPerm::haveFieldPermVersionen($this->stgteil, MvvPerm::PERM_READ)) {
-            throw new Trails_Exception(403);
+            throw new Trails\Exception(403);
         }
 
         if (!isset($this->version)) {
             $this->version = StgteilVersion::find($version_id);
             if (!$this->version) {
                 if (!MvvPerm::haveFieldPermVersionen($this->stgteil, MvvPerm::PERM_CREATE)) {
-                    throw new Trails_Exception(403);
+                    throw new Trails\Exception(403);
                 }
                 $this->version = new StgteilVersion();
             }
@@ -51,7 +51,7 @@ abstract class SharedVersionController extends MVVController
         if (Request::submitted('store')) {
             CSRFProtection::verifyUnsafeRequest();
             if (!MvvPerm::haveFieldPermVersionen($this->stgteil)) {
-                throw new Trails_Exception(403);
+                throw new Trails\Exception(403);
             }
             $stored = false;
             $this->version->stgteil_id = $this->stgteil->getId();
@@ -220,7 +220,7 @@ abstract class SharedVersionController extends MVVController
     {
         $version = StgteilVersion::find($version_id);
         if (!$version) {
-             throw new Trails_Exception(404, _('Unbekannte Version'));
+             throw new Trails\Exception(404, _('Unbekannte Version'));
         }
         if (Request::isPost()) {
             CSRFProtection::verifyUnsafeRequest();
@@ -267,16 +267,16 @@ abstract class SharedVersionController extends MVVController
         $perm = MvvPerm::get($this->version);
 
         if (!$perm->haveFieldPerm('abschnitte', MvvPerm::PERM_READ)) {
-            throw new Trails_Exception(403);
+            throw new Trails\Exception(403);
         }
         if ($this->abschnitt->isNew() && !$perm->haveFieldPerm('abschnitte', MvvPerm::PERM_CREATE)) {
-            throw new Trails_Exception(403);
+            throw new Trails\Exception(403);
         }
 
         if (Request::submitted('store')) {
             CSRFProtection::verifyUnsafeRequest();
             if (!$perm->haveFieldPerm('abschnitte', MvvPerm::PERM_WRITE)) {
-                throw new Trails_Exception(403);
+                throw new Trails\Exception(403);
             }
             $this->abschnitt->version_id = $this->version->getId();
             $this->abschnitt->name = Request::i18n('name')->trim();
@@ -494,7 +494,7 @@ abstract class SharedVersionController extends MVVController
         $abschnitt = StgteilAbschnitt::find($abschnitt_id);
         if ($abschnitt) {
             if (!MvvPerm::haveFieldPermModul_zuordnungen($abschnitt, MvvPerm::PERM_CREATE)) {
-                throw new Trails_Exception(403);
+                throw new Trails\Exception(403);
             }
             $modul = Modul::find($modul_id);
             if (!$modul) {
@@ -614,7 +614,7 @@ abstract class SharedVersionController extends MVVController
     {
         $version = StgteilVersion::find($version_id);
         if (!$version) {
-             throw new Trails_Exception(404, _('Unbekannte Version'));
+             throw new Trails\Exception(404, _('Unbekannte Version'));
         } else {
             if (Request::isPost()) {
                 CSRFProtection::verifyUnsafeRequest();
@@ -754,7 +754,7 @@ abstract class SharedVersionController extends MVVController
                     $this->redirect($this->action_url('abschnitte/' . $version_id));
                 }
             } else {
-                throw new Trails_Exception(403);
+                throw new Trails\Exception(403);
             }
         }
         if (Request::isXhr()) {
diff --git a/app/controllers/studiengaenge/studiengaenge.php b/app/controllers/studiengaenge/studiengaenge.php
index d053f48..8465665 100644
--- a/app/controllers/studiengaenge/studiengaenge.php
+++ b/app/controllers/studiengaenge/studiengaenge.php
@@ -541,7 +541,7 @@ class Studiengaenge_StudiengaengeController extends MVVController
                 if (Request::isPost()) {
                     CSRFProtection::verifyRequest();
                     if (!MvvPerm::haveFieldPermStudiengangteile($studiengang, MvvPerm::PERM_CREATE)) {
-                        throw new Trails_Exception(403);
+                        throw new Trails\Exception(403);
                     }
                     $stgteil_name = $this->stg_stgteil->stgteil_name;
                     $stgbez_name = $this->stg_stgteil->stgbez_name;
@@ -588,7 +588,7 @@ class Studiengaenge_StudiengaengeController extends MVVController
                 if (Request::isPost()) {
                     CSRFProtection::verifyUnsafeRequest();
                     if (!MvvPerm::haveFieldPermStudiengangteile($studiengang, MvvPerm::PERM_CREATE)) {
-                        throw new Trails_Exception(403);
+                        throw new Trails\Exception(403);
                     }
                     $stgteil_name = $stg_stgteil->stgteil_name;
                     $stgbez_name = $stg_stgteil->stgbez_name;
diff --git a/app/controllers/studiengaenge/studiengangteile.php b/app/controllers/studiengaenge/studiengangteile.php
index 0fddd44..bc1449f 100644
--- a/app/controllers/studiengaenge/studiengangteile.php
+++ b/app/controllers/studiengaenge/studiengangteile.php
@@ -144,7 +144,7 @@ class Studiengaenge_StudiengangteileController extends SharedVersionController
             $this->stgteil->contact_assignments = $stgteil_orig->contact_assignments;
 
         } else {
-            throw new Trails_Exception(404);
+            throw new Trails\Exception(404);
         }
         $this->perform_relayed('stgteil');
     }
diff --git a/app/controllers/studiengaenge/versionen.php b/app/controllers/studiengaenge/versionen.php
index 9b60b3d..41625bf 100644
--- a/app/controllers/studiengaenge/versionen.php
+++ b/app/controllers/studiengaenge/versionen.php
@@ -52,7 +52,7 @@ class Studiengaenge_VersionenController extends SharedVersionController
                 $this->redirect($this->action_url('index/' .  $this->chooser_filter['stgteile']));
                 return;
             default :
-                throw new Trails_Exception(400);
+                throw new Trails\Exception(400);
         }
         $this->name = $list;
         if (!empty($this->lists[$list]['elements'])) {
@@ -218,7 +218,7 @@ class Studiengaenge_VersionenController extends SharedVersionController
         if ($stgteil_id) {
             $this->stgteil = StudiengangTeil::find($stgteil_id);
             if (!$this->stgteil) {
-                throw new Trails_Exception(404, _('Unbekannter Studiengangteil'));
+                throw new Trails\Exception(404, _('Unbekannter Studiengangteil'));
             }
 
             $this->initPageParams();
diff --git a/app/controllers/studip_controller.php b/app/controllers/studip_controller.php
deleted file mode 100644
index 9e238a1..0000000
--- a/app/controllers/studip_controller.php
+++ /dev/null
@@ -1,875 +0,0 @@
-<?php
-/*
- * studip_controller.php - studip controller base class
- * Copyright (c) 2009  Elmar Ludwig
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- */
-
-use PhpOffice\PhpSpreadsheet\Spreadsheet;
-use PhpOffice\PhpSpreadsheet\Writer\Csv;
-use PhpOffice\PhpSpreadsheet\Writer\Xlsx;
-
-require_once 'studip_controller_properties_trait.php';
-require_once 'studip_response.php';
-
-/**
- * @property StudipResponse $response
- */
-abstract class StudipController extends Trails_Controller
-{
-    use StudipControllerPropertiesTrait;
-
-    protected $with_session = false; //do we need to have a session for this controller
-    protected $allow_nobody = true; //should 'nobody' allowed for this controller or redirected to login?
-    protected $_autobind = false;
-
-    /**
-     * @return false|void
-     */
-    public function before_filter(&$action, &$args)
-    {
-        $this->current_action = $action;
-        // allow only "word" characters in arguments
-        $this->validate_args($args);
-
-        parent::before_filter($action, $args);
-
-        if ($this->with_session) {
-            # open session
-            page_open([
-                'sess' => 'Seminar_Session',
-                'auth' => $this->allow_nobody ? 'Seminar_Default_Auth' : 'Seminar_Auth',
-                'perm' => 'Seminar_Perm',
-                'user' => 'Seminar_User'
-            ]);
-
-            // show login-screen, if authentication is "nobody"
-            $GLOBALS['auth']->login_if((Request::get('again') || !$this->allow_nobody) && $GLOBALS['user']->id == 'nobody');
-
-            // Setup flash instance
-            $this->flash = Trails_Flash::instance();
-
-            // set up user session
-            include 'lib/seminar_open.php';
-        }
-
-        // Set generic attribute that indicates whether the request was sent
-        // via ajax or not
-        $this->via_ajax = Request::isXhr();
-
-        # Set base layout
-        #
-        # If your controller needs another layout, overwrite your controller's
-        # before filter:
-        #
-        #   class YourController extends AuthenticatedController {
-        #     function before_filter(&$action, &$args) {
-        #       parent::before_filter($action, $args);
-        #       $this->set_layout("your_layout");
-        #     }
-        #   }
-        #
-        # or unset layout by sending:
-        #
-        #   $this->set_layout(NULL)
-        #
-        $layout_file = Request::isXhr()
-                     ? 'layouts/dialog.php'
-                     : 'layouts/base.php';
-        $layout = $GLOBALS['template_factory']->open($layout_file);
-        $this->set_layout($layout);
-
-        $this->set_content_type('text/html;charset=utf-8');
-    }
-
-    /**
-     * Extended method to inject extended response object.
-     */
-    public function erase_response()
-    {
-        parent::erase_response();
-
-        $this->response = new StudipResponse();
-    }
-
-    /**
-     * Hooked perform method in order to inject body element id creation.
-     *
-     * In order to avoid clashes, these body element id will be joined
-     * with a minus sign. Otherwise the controller "x" with action
-     * "y_z" would be given the same id as the controller "x/y" with
-     * the action "z", namely "x_y_z". With the minus sign this will
-     * result in the ids "x-y_z" and "x_y-z".
-     *
-     * Plugins will always have a leading 'plugin-' and the decamelized
-     * plugin name in front of the id.
-     *
-     * @param String $unconsumed_path Path segment containing action and
-     *                                optionally arguments or format
-     * @return Trails_Response from parent controller
-     */
-    public function perform($unconsumed_path)
-    {
-        // Set body element id if it has not already been set
-        if (!PageLayout::hasBodyElementId()) {
-            $body_id = $this->getBodyElementIdForControllerAndAction($unconsumed_path);
-            PageLayout::setBodyElementId($body_id);
-        }
-
-        return parent::perform($unconsumed_path);
-    }
-
-    /**
-     * Callback function being called after an action is executed.
-     *
-     * @param string Name of the action to perform.
-     * @param array  An array of arguments to the action.
-     *
-     * @return void
-     */
-    public function after_filter($action, $args)
-    {
-        parent::after_filter($action, $args);
-
-        if (Request::isXhr() && !isset($this->response->headers['X-Title']) && PageLayout::hasTitle()) {
-            $this->response->add_header('X-Title', rawurlencode(PageLayout::getTitle()));
-        }
-        if (Request::isXhr() && !isset($this->response->headers['X-WikiLink']) && PageLayout::getHelpKeyword()) {
-            $this->response->add_header('X-WikiLink', format_help_url(PageLayout::getHelpKeyword()));
-        }
-
-        if ($this->with_session) {
-            page_close();
-        }
-    }
-
-    /**
-     * Validate arguments based on a list of given types. The types are:
-     * 'int', 'float', 'option' and 'string'. If the list of types is NULL
-     * or shorter than the argument list, 'option' is assumed for all
-     * remaining arguments. 'option' differs from Request::option() in
-     * that it also accepts the charaters '-' and ',' in addition to all
-     * word characters.
-     *
-     * Since Stud.IP 4.0 it is also possible to directly inject
-     * SimpleORMap objects. If types is NULL, the signature of the called
-     * action is analyzed and any type hint that matches a sorm class
-     * will be used to create an object using the argument as the id
-     * that is passed to the object's constructor.
-     *
-     * If $_autobind is set to true, the created object is also assigned
-     * to the controller so that it is available in a view.
-     *
-     * @param array $args  an array of arguments to the action
-     * @param array $types list of argument types (optional)
-     */
-    public function validate_args(&$args, $types = null)
-    {
-        $class_infos = [];
-
-        if ($types === null) {
-            $types = [];
-        }
-
-        if ($this->has_action($this->current_action)) {
-            $reflection = new ReflectionMethod($this, $this->current_action . '_action');
-            $parameters = $reflection->getParameters();
-            foreach ($parameters as $i => $parameter) {
-                $class_type = $parameter->getType();
-
-                if (
-                    !$class_type
-                    || !class_exists($class_type->getName())
-                    || !is_a($class_type->getName(), SimpleORMap::class, true)
-                ) {
-                    continue;
-                }
-
-                $types[$i] = 'sorm';
-                $class_infos[$i] = [
-                    'model'    => $class_type->getName(),
-                    'var'      => $parameter->getName(),
-                    'optional' => $parameter->isOptional(),
-                ];
-
-                if ($parameter->isOptional() && !isset($args[$i])) {
-                    $args[$i] = $parameter->getDefaultValue();
-                }
-            }
-        }
-
-        foreach ($args as $i => &$arg) {
-            $type = $types[$i] ?? 'option';
-            switch ($type) {
-                case 'int':
-                    $arg = (int) $arg;
-                    break;
-
-                case 'float':
-                    $arg = (float) strtr($arg, ',', '.');
-                    break;
-
-                case 'option':
-                    if (preg_match('/[^\\w,-]/', $arg)) {
-                        throw new Trails_Exception(400);
-                    }
-                    break;
-
-                case 'sorm':
-                    $info = $class_infos[$i];
-
-                    $id = null;
-                    if ($arg != -1) {
-                        $id = $arg;
-                    }
-                    if (mb_strpos($id, SimpleORMap::ID_SEPARATOR) !== false) {
-                        $id = explode(SimpleORMap::ID_SEPARATOR, $id);
-                    }
-
-                    $reflection = new ReflectionClass($info['model']);
-
-                    $sorm = $reflection->newInstance($id);
-                    if (!$info['optional'] && $sorm->isNew()) {
-                        throw new Trails_Exception(
-                            404,
-                            "Parameter {$info['var']} could not be resolved with value {$arg}"
-                        );
-                    }
-
-                    $arg = $sorm;
-                    if ($this->_autobind) {
-                        $this->{$info['var']} = $arg;
-                    }
-                    break;
-
-                case 'string':
-                    break;
-
-                default:
-                    throw new Trails_Exception(500, 'Unknown type "' . $type . '"');
-            }
-        }
-
-        reset($args);
-    }
-
-    /**
-     * Returns a URL to a specified route to your Trails application.
-     * without first parameter the current action is used
-     * if route begins with a / then the current controller ist prepended
-     * if second parameter is an array it is passed to URLHeper
-     *
-     * @param  string   a string containing a controller and optionally an action
-     * @param  string[] optional arguments
-     *
-     * @return string  a URL to this route
-     */
-    public function url_for($to = ''/* , ... */)
-    {
-        $args = func_get_args();
-
-        // Try to create route if none given
-        if ($to === '') {
-            $args[0] = isset($this->parent_controller)
-                     ? $this->parent_controller->current_action
-                     : $this->current_action;
-            return $this->action_url(...$args);
-        }
-
-        // Create url for a specific action
-        // TODO: This seems odd. You kinda specify an absolute path
-        //       to receive a relative url. Meh...
-        //
-        // @deprecated Do not use this, please!
-        if ($to[0] === '/') {
-            $args[0] = substr($to, 1);
-            return $this->action_url(...$args);
-        }
-
-        // Check for absolute URL
-        if ($this->isURL($to)) {
-            throw new InvalidArgumentException(__METHOD__ . ' cannot be used with absolute URLs');
-        }
-
-        // Extract fragment (if any)
-        if (strpos($to, '#') !== false) {
-            list($args[0], $fragment) = explode('#', $to);
-        }
-
-        // Extract parameters (if any)
-        $params = [];
-        if (is_array(end($args))) {
-            $params = array_pop($args);
-        }
-
-        // Map any sorm objects to their ids
-        $args = array_map(function ($arg) {
-            if (is_object($arg) && $arg instanceof SimpleORMap) {
-                return $arg->isNew() ? -1 : $arg->id;
-            }
-            return $arg;
-        }, $args);
-
-        $url = parent::url_for(...$args);
-
-        if (isset($fragment)) {
-            $url .= '#' . $fragment;
-        }
-        return URLHelper::getURL($url, $params);
-    }
-
-    /**
-     * Returns an escaped URL to a specified route to your Trails application.
-     * without first parameter the current action is used
-     * if route begins with a / then the current controller ist prepended
-     * if second parameter is an array it is passed to URLHeper
-     *
-     * @param  string   a string containing a controller and optionally an action
-     * @param  strings  optional arguments
-     *
-     * @return string  a URL to this route
-     */
-    public function link_for($to = ''/* , ... */)
-    {
-        return htmlReady($this->url_for(...func_get_args()));
-    }
-
-    /**
-     * Redirects the user another page. Accepts multiple parameters just like
-     * url_for().
-     *
-     * @param string $to
-     * @see StudipController::url_for()
-     */
-    public function redirect($to)
-    {
-        $to = $this->adjustToArguments(...func_get_args());
-
-        parent::redirect($to);
-    }
-
-    /**
-     * Relocate the user to another location. This is a specialized version
-     * of redirect that differs in two points:
-     *
-     * - relocate() will force the browser to leave the current dialog while
-     *   redirect would refresh the dialog's contents
-     * - relocate() accepts all the parameters that url_for() accepts so it's
-     *   no longer neccessary to chain url_for() and redirect()
-     *
-     * @param String $to Location to redirect to
-     */
-    public function relocate($to)
-    {
-        $to = $this->adjustToArguments(...func_get_args());
-
-        if (Request::isDialog()) {
-            $this->response->add_header('X-Location', encodeURI($to));
-            $this->render_nothing();
-        } else {
-            parent::redirect($to);
-        }
-    }
-
-    /**
-     * Returns a URL to a specified route to your Trails application, unless
-     * the parameter is already a valid URL (which is returned unchanged).
-     *
-     * If no absolute url or more than one argument is given, url_for() is
-     * used.
-     */
-    private function adjustToArguments(...$args): string
-    {
-        if (count($args) > 1 && $this->isURL($args[0])) {
-            throw new InvalidArgumentException('Method may not be used with a URL and multiple parameters');
-        }
-
-        if (count($args) === 1 && $this->isURL($args[0])) {
-            return $args[0];
-        }
-
-        return $this->url_for(...$args);
-    }
-
-    /**
-     * Returns whether the given parameter is a valid url.
-     *
-     * @param string $to
-     * @return bool
-     */
-    private function isURL(string $to): bool
-    {
-        return preg_match('#^(/|\w+://)#', $to);
-    }
-
-    /**
-     * Exception handler called when the performance of an action raises an
-     * exception.
-     *
-     * @param  object     the thrown exception
-     */
-    public function rescue($exception)
-    {
-        throw $exception;
-    }
-
-    /**
-     * render given data as json, data is converted to utf-8
-     *
-     * @param mixed $data
-     */
-    public function render_json($data)
-    {
-        $json = json_encode($data);
-
-        $this->set_content_type('application/json;charset=utf-8');
-        $this->response->add_header('Content-Length', strlen($json));
-        $this->render_text($json);
-    }
-
-    /**
-     * Render given data as csv, data is assumed to be utf-8.
-     * The first row of data may contain column titles.
-     *
-     * @param array $data       data as two dimensional array
-     * @param string $filename  download file name (optional)
-     * @param string $delimiter field delimiter char (optional)
-     * @param string $enclosure field enclosure char (optional)
-     */
-    public function render_csv($data, $filename = null, $delimiter = ';', $enclosure = '"')
-    {
-        $this->set_content_type('text/csv; charset=UTF-8');
-
-        $output = fopen('php://temp', 'rw');
-        fputs($output, "\xEF\xBB\xBF");
-
-        foreach ($data as $row) {
-            fputcsv($output, $row, $delimiter, $enclosure);
-        }
-
-        rewind($output);
-        $csv_data = stream_get_contents($output);
-        fclose($output);
-
-        if (isset($filename)) {
-            $this->response->add_header('Content-Disposition', 'attachment; ' . encode_header_parameter('filename', $filename));
-        }
-
-        $this->response->add_header('Content-Length', strlen($csv_data));
-
-        $this->render_text($csv_data);
-    }
-
-    /**
-     * Renders a pdf file given by a TCPDF/ExportPDF object.
-     *
-     * @param TCPDF   $pdf      TCPDF object to render
-     * @param string  $filename Filename
-     * @param bool    $inline   Should the pdf be displayed inline (default: no)
-     */
-    protected function render_pdf(TCPDF $pdf, $filename, $inline = false)
-    {
-        $temp_file = $GLOBALS['TMP_PATH'] . '/' . md5(uniqid('pdf-file', true));
-        $pdf->Output($temp_file, 'F');
-
-        $disposition = $inline ? 'inline' : 'attachment';
-
-        $this->render_temporary_file($temp_file, $filename, 'application/pdf', $disposition);
-    }
-
-    /**
-     * Renders a file
-     * @param string  $file                Path of the file to render
-     * @param string  $filename            Name of the file displayed to user
-     *                                     (will equal $file when missing)
-     * @param string  $content_type        Optional content type (will be determined if missing)
-     * @param string  $content_disposition Either attachment (default) or inline
-     * @param Closure $callback            Optional callback when download has finished
-     * @param int     $chunk_size          Optional size of chunks to send (default: 256k)
-     */
-    public function render_file(
-        $file,
-        $filename = null,
-        $content_type = null,
-        $content_disposition = 'attachment',
-        Closure $callback = null,
-        $chunk_size = 262144
-    ) {
-        if (!file_exists($file)) {
-            throw new Trails_Exception(404);
-        }
-
-        if (!is_readable($file)) {
-            throw new Trails_Exception(500);
-        }
-
-        if ($content_type === null) {
-            $content_type = get_mime_type($filename ?: $file);
-        }
-
-        if (!in_array($content_type, get_mime_types())) {
-            $content_type = 'application/octet-stream';
-        }
-
-        if ($content_type === 'application/octet-stream') {
-            $content_disposition = 'attachment';
-        }
-
-        $this->set_content_type($content_type);
-        $this->response->add_header(
-            'Content-Disposition',
-            "{$content_disposition}; " . encode_header_parameter(
-                'filename',
-                FileManager::cleanFileName($filename ?: basename($file))
-            )
-        );
-        $this->response->add_header('Content-Length', filesize($file));
-        $this->response->add_header('Content-Transfer-Encoding',  'binary');
-        $this->response->add_header('Pragma', 'public');
-        $this->render_text(function () use ($file, $chunk_size, $callback) {
-            $fp = fopen($file, 'rb');
-
-            while (!feof($fp)) {
-                yield fgets($fp, $chunk_size);
-            }
-
-            fclose($fp);
-
-            if ($callback) {
-                $callback($file);
-            }
-        });
-    }
-
-    /**
-     * Renders a temporary file which will be deleted after transmission.
-     * This is just a convenience method so you don't have to write the delete
-     * callback.
-     *
-     * @param string  $file                Path of the file to render
-     * @param string  $filename            Name of the file displayed to user
-     *                                     (will equal $file when missing)
-     * @param string  $content_type        Optional content type (will be determined if missing)
-     * @param string  $content_disposition Either attachment (default) or inline
-     * @param Closure $callback            Optional callback when download has finished
-     * @param int     $chunk_size          Optional size of chunks to send (default: 256k)
-     */
-    public function render_temporary_file(
-        $file,
-        $filename = null,
-        $content_type = null,
-        $content_disposition = 'attachment',
-        Closure $callback = null,
-        $chunk_size = 262144
-
-    ) {
-        $delete_callback = function ($file) use ($callback) {
-            unlink($file);
-
-            if ($callback) {
-                $callback($file);
-            }
-        };
-
-        $this->render_file(
-            $file,
-            $filename,
-            $content_type,
-            $content_disposition,
-            $delete_callback,
-            $chunk_size
-        );
-    }
-
-    public function render_form(\Studip\Forms\Form $form)
-    {
-        $this->render_text($form->render());
-    }
-
-    /**
-     * relays current request to another controller and returns the response
-     * the other controller is given all assigned properties, additional parameters are passed
-     * through
-     *
-     * @param string $to_uri a trails route
-     * @return Trails_Response
-     */
-    public function relay($to_uri/* , ... */)
-    {
-        $args = func_get_args();
-        $uri = array_shift($args);
-        [$controller_path, $unconsumed] = '' === $uri ? $this->dispatcher->default_route() : $this->dispatcher->parse($uri);
-
-        $controller = $this->dispatcher->load_controller($controller_path);
-        $assigns = $this->get_assigned_variables();
-        unset($assigns['controller']);
-        foreach ($assigns as $k => $v) {
-            $controller->$k = $v;
-        }
-        $controller->layout = null;
-        $controller->parent_controller = $this;
-        array_unshift($args, $unconsumed);
-        return $controller->perform_relayed(...$args);
-    }
-
-    /**
-     * Relays current request and performs redirect if neccessary.
-     *
-     * @param string $to_uri a trails route
-     * @return Trails_Response
-     *
-     * @see StudipController::relay()
-     */
-    public function relayWithRedirect(...$args): Trails_Response
-    {
-        $response = $this->relay(...$args);
-
-        // If the relayed action should perform a redirect, do so
-        if (isset($response->headers['Location'])) {
-            header("Location: {$response->headers['Location']}");
-            page_close();
-            die;
-        }
-
-        return $response;
-    }
-
-    /**
-     * perform a given action/parameter string from an relayed request
-     * before_filter and after_filter methods are not called
-     *
-     * @see perform
-     * @param string $unconsumed
-     * @return Trails_Response
-     */
-    public function perform_relayed($unconsumed/* , ... */)
-    {
-        $args = func_get_args();
-        $unconsumed = array_shift($args);
-
-        [$action, $extracted_args, $format] = $this->extract_action_and_args($unconsumed);
-        $this->format = isset($format) ? $format : 'html';
-        $this->current_action = $action;
-        $args = array_merge($extracted_args, $args);
-        $callable = $this->map_action($action);
-
-        if (is_callable($callable)) {
-            $callable(...$args);
-        } else {
-            $this->does_not_understand($action, $args);
-        }
-
-        if (!$this->performed) {
-            $this->render_action($action);
-        }
-        return $this->response;
-    }
-
-    /**
-     * Renders a given template and returns the resulting string.
-     *
-     * @param string $template Name of the template file
-     * @param mixed  $layout   Optional layout
-     * @return string
-     */
-    public function render_template_as_string($template, $layout = null)
-    {
-        $template = $this->get_template_factory()->open($template);
-        $template->set_layout($layout);
-        $template->set_attributes($this->get_assigned_variables());
-        return $template->render();
-    }
-
-    /**
-     * Magic methods that intercepts all unknown method calls.
-     * If a method is called that matches an action on this controller,
-     * an url to that action is generated.
-     *
-     * Basically, this:
-     *
-     *    <code>$controller->url_for('foo/bar/baz/' . $param)</code>
-     *
-     * is equal to calling this on the Foo_BarController:
-     *
-     *    <code>$controller->baz($param)</code>
-     *
-     * @param String $method    Called method name
-     * @param array  $argumetns Provided arguments
-     * @return url to the requested action
-     * @throws Trails_UnknownAction if no action matches the method
-     */
-    public function __call($method, $arguments)
-    {
-        $function = 'action_link';
-        if (mb_strpos($method, 'Link') === mb_strlen($method) - 4) {
-            $method = mb_substr($method, 0, -4);
-        } elseif (mb_strpos($method, 'URL') === mb_strlen($method) - 3) {
-            $function = 'action_url';
-            $method = mb_substr($method, 0, -3);
-        }
-
-        if (!$this->has_action($method)) {
-            throw new Trails_UnknownAction("Unknown action '{$method}'");
-        }
-
-        array_unshift($arguments, $method);
-        return call_user_func_array([$this, $function], $arguments);
-    }
-
-    /**
-     * Returns whether this controller has the specificed action.
-     *
-     * @param string $action Name of the action
-     * @return true if action is defined, false otherwise
-     */
-    public function has_action($action)
-    {
-        return method_exists($this, $action . '_action')
-            || ($this->parent_controller
-                && $this->parent_controller->has_action($action));
-    }
-
-    /**
-     * Generates the url for an action on this controller without the
-     * neccessity to provide the full "path" to the action (since it
-     * is implicitely known).
-     *
-     * Basically, this:
-     *
-     *    <code>$controller->url_for('foo/bar/baz/' . $param)</code>
-     *
-     * is equal to calling this on the Foo_BarController:
-     *
-     *    <code>$controller->action_url('baz/' . $param)</code>
-     *
-     * @param string $action Name of the action
-     * @return string url to the requested action
-     */
-    public function action_url($action)
-    {
-        $arguments = func_get_args();
-        $arguments[0] = $this->controller_path() . '/' . $arguments[0];
-
-        return $this->url_for(...$arguments);
-    }
-
-    /**
-     * Generates the link for an action on this controller without the
-     * neccessity to provide the full "path" to the action (since it
-     * is implicitely known).
-     *
-     * Basically, this:
-     *
-     *    <code>$controller->link_for('foo/bar/baz/' . $param)</code>
-     *
-     * is equal to calling this on the Foo_BarController:
-     *
-     *    <code>$controller->action_link('baz/' . $param)</code>
-     *
-     * @param string $action Name of the action
-     * @return string to the requested action
-     */
-    public function action_link($action)
-    {
-        return htmlReady($this->action_url(...func_get_args()));
-    }
-
-    /**
-     * Returns the url path to this controller.
-     *
-     * @return string url path to this controller
-     */
-    protected function controller_path()
-    {
-        $class = get_class($this->parent_controller ?? $this);
-        $controller = mb_substr($class, 0, -mb_strlen('Controller'));
-        $controller = strtosnakecase($controller);
-        return preg_replace('/_{2,}/', '/', $controller);
-    }
-
-
-    /**
-     * Validate the datetime according to specific format.
-     *
-     * @param string $datetime the datetime which should be validate
-     * @param string $format the format that the datetime should have by default H:i for time
-     *
-     * @return bool result of validation
-     */
-    public function validate_datetime($datetime, $format = 'H:i')
-    {
-        $dt = DateTime::createFromFormat($format, $datetime);
-        return $dt && $dt->format($format) == date('H:i',strtotime($datetime));
-    }
-
-    /**
-     * Export xlsx and csv files via PhpSpreadsheet
-     *
-     * @throws \PhpOffice\PhpSpreadsheet\Writer\Exception
-     */
-    public function render_spreadsheet(
-        array $header,
-        array $data,
-        string $format,
-        string $filename,
-        ?string $filepath = null
-    ): void  {
-        $render_to_browser = false;
-        if ($filepath == null) {
-            $render_to_browser = true;
-            $filepath = tempnam($GLOBALS['TMP_PATH'], 'spreadsheet');
-        }
-        $spreadsheet = new Spreadsheet();
-        $activeWorksheet = $spreadsheet->getActiveSheet();
-        $activeWorksheet->fromArray($header);
-        $activeWorksheet->fromArray($data, null, 'A2');
-
-        if ($format === 'xlsx') {
-            $writer = new Xlsx($spreadsheet);
-        } elseif ($format === 'csv') {
-            $writer = new Csv($spreadsheet);
-        } else {
-            throw new Exception("Format {$format} is not supported");
-        }
-
-        $writer->save($filepath);
-
-        if ($render_to_browser) {
-            $this->response->add_header('Cache-Control', 'cache, must-revalidate');
-            $this->render_temporary_file(
-                $filepath,
-                $filename,
-                'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'
-            );
-        }
-    }
-
-    /**
-     * Creates the body element id for this controller a given action.
-     *
-     * @param string $unconsumed_path Unconsumed path to extract action from
-     * @return string
-     */
-    protected function getBodyElementIdForControllerAndAction($unconsumed_path)
-    {
-        // Extract action from unconsumed path segment
-        [$action] = $this->extract_action_and_args($unconsumed_path);
-
-        // Extract controller name from class name
-        $controller = preg_replace('/Controller$/', '', get_class($this));
-        $controller = Trails_Inflector::underscore($controller);
-
-        // Build main parts of the body element id
-        $body_id_parts = explode('/', $controller);
-        $body_id_parts[] = $action;
-
-        // Create and set body element id
-        $body_id = implode('-', $body_id_parts);
-
-        return $body_id;
-    }
-}
diff --git a/app/controllers/studip_controller_properties_trait.php b/app/controllers/studip_controller_properties_trait.php
deleted file mode 100644
index 4e906fa..0000000
--- a/app/controllers/studip_controller_properties_trait.php
+++ /dev/null
@@ -1,69 +0,0 @@
-<?php
-/**
- * This trait manages all variable assignments to the controller and templates.
- *
- * @author Jan-Hendrik Willms <tleilax+studip@gmail.com>
- * @license GPL2 or any later version
- * @since Stud.IP 5.2
- */
-trait StudipControllerPropertiesTrait
-{
-    /**
-     * Stores the assigned variables.
-     * @var array
-     */
-    protected $_template_variables = [];
-
-    /**
-     * Returns whether a variable is set.
-     *
-     * @param string $offset
-     * @return bool
-     */
-    public function __isset(string $offset): bool
-    {
-        return isset($this->_template_variables[$offset]);
-    }
-
-    /**
-     * Stores a variable.
-     *
-     * @param string $offset
-     * @param mixed $value
-     */
-    public function __set(string $offset, $value): void
-    {
-        $this->_template_variables[$offset] = $value;
-    }
-
-    /**
-     * Returns a previously set variable.
-     *
-     * @param string $offset
-     * @return mixed
-     */
-    public function &__get(string $offset)
-    {
-        if (!isset($this->_template_variables[$offset])) {
-            $this->_template_variables[$offset] = null;
-        }
-        return $this->_template_variables[$offset];
-    }
-
-    /**
-     * Unsets a previously set variable
-     *
-     * @param string $offset
-     */
-    public function __unset(string $offset): void
-    {
-        unset($this->_template_variables[$offset]);
-    }
-
-    public function get_assigned_variables(): array
-    {
-        $variables = $this->_template_variables;
-        $variables['controller'] = $this;
-        return $variables;
-    }
-}
diff --git a/app/controllers/studip_response.php b/app/controllers/studip_response.php
deleted file mode 100644
index 1c15326..0000000
--- a/app/controllers/studip_response.php
+++ /dev/null
@@ -1,55 +0,0 @@
-<?php
-class StudipResponse extends Trails_Response
-{
-    /**
-     * Outputs this response to the client using "echo" and "header".
-     *
-     * This extension allows the body to be a callable and handles generators
-     * by outputting the chunks yielded by the generator.
-     */
-    public function output()
-    {
-        if (isset($this->status)) {
-            $this->send_header(
-                "{$_SERVER['SERVER_PROTOCOL']} {$this->status} {$this->reason}",
-                true,
-                $this->status
-            );
-        }
-
-        // Send headers
-        foreach ($this->headers as $k => $v) {
-            $this->send_header("{$k}: {$v}");
-        }
-
-        // Determine output
-        if (is_callable($this->body)) {
-            $output = call_user_func($this->body);
-        } else {
-            $output = $this->body;
-        }
-
-        if ($output instanceof Generator) {
-            // Clear output buffer
-            while (ob_get_level()) {
-                ob_end_clean();
-            }
-
-            // Ensure generator will run to the end
-            $abort = ignore_user_abort(true);
-
-            // Output chunks yielded by generator
-            foreach ($output as $chunk) {
-                if (!connection_aborted()) {
-                    echo $chunk;
-                    flush();
-                }
-            }
-
-            // Reset user abort to previous state
-            ignore_user_abort($abort);
-        } else {
-            echo $output;
-        }
-    }
-}
diff --git a/app/controllers/vote.php b/app/controllers/vote.php
deleted file mode 100644
index 19f92a2..0000000
--- a/app/controllers/vote.php
+++ /dev/null
@@ -1,94 +0,0 @@
-<?php
-
-# Lifter010: TODO
-/**
- * vote.php - Votecontroller controller
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License as
- * published by the Free Software Foundation; either version 2 of
- * the License, or (at your option) any later version.
- */
-
-class VoteController extends AuthenticatedController {
-
-    public function display_action($range_id) {
-
-        // Bind some params
-        URLHelper::bindLinkParam('show_expired', $null1);
-        URLHelper::bindLinkParam('preview', $null2);
-        URLHelper::bindLinkParam('revealNames', $null3);
-        URLHelper::bindLinkParam('sort', $null4);
-
-        // Bind range_id
-        $this->range_id = $range_id;
-
-        $this->nobody = !$GLOBALS['user']->id || $GLOBALS['user']->id == 'nobody';
-
-        /*
-         * Insert vote
-         */
-        if ($vote = Request::get('vote')) {
-            $vote = new Vote($vote);
-            if (!$this->nobody && $vote && $vote->isRunning() && (!$vote->userVoted() || $vote->changeable)) {
-                try {
-                    $vote->insertVote(Request::getArray('vote_answers'), $GLOBALS['user']->id);
-                } catch (Exception $exc) {
-                    $GLOBALS['vote_message'][$vote->id] = MessageBox::error($exc->getMessage());
-                }
-            }
-        }
-
-        // Check if we need administration icons
-        $this->admin = $range_id == $GLOBALS['user']->id || $GLOBALS['perm']->have_studip_perm('tutor', $range_id);
-
-
-        // Load evaluations
-        if (!$this->nobody) {
-            $eval_db = new EvaluationDB();
-            $this->evaluations = StudipEvaluation::findMany($eval_db->getEvaluationIDs($range_id, EVAL_STATE_ACTIVE));
-        } else {
-            $this->evaluations = [];
-        }
-        $show_votes[] = 'active';
-        // Check if we got expired
-        if (Request::get('show_expired')) {
-            $show_votes[] = 'stopvis';
-            if ($this->admin) {
-                $this->evaluations = array_merge($this->evaluations, StudipEvaluation::findMany($eval_db->getEvaluationIDs($range_id, EVAL_STATE_STOPPED)));
-                $show_votes[] = 'stopinvis';
-            }
-        }
-
-        $this->votes = Vote::findBySQL('range_id = ? AND state IN (?) ORDER BY mkdate desc', [$range_id,$show_votes]);
-        $this->visit();
-
-        }
-
-    function visit()
-    {
-        if ($GLOBALS['user']->id && $GLOBALS['user']->id != 'nobody' && Request::option('contentbox_open') && in_array(Request::option('contentbox_type'), words('vote eval'))) {
-            object_set_visit(Request::option('contentbox_open'), Request::option('contentbox_type'));
-        }
-    }
-
-    function visit_action()
-    {
-        $this->visit();
-        $this->render_nothing();
-    }
-
-    /**
-     * Determines if a vote should show its result
-     *
-     * @param Vote $vote the vote to check
-     * @return boolean true if result should be shown
-     */
-    public function showResult($vote) {
-        if (Request::submitted('change') && $vote->changeable) {
-            return false;
-        }
-        return $vote->userVoted() || in_array($vote->id, Request::getArray('preview'));
-    }
-
-}