fix error from 2073417431ac81e578e40bc199ed520b87b51a0d on branch 6.0, re #6369

1 files changed, 1 insertions, 0 deletions

diff --git a/app/controllers/course/details.php b/app/controllers/course/details.php
index 0edba4a..5336636 100644
--- a/app/controllers/course/details.php
+++ b/app/controllers/course/details.php
@@ -131,6 +131,7 @@ class Course_DetailsController extends AuthenticatedController
                             // flatten the paths to a linked list
                             $parent_id = 'root';
                             foreach ($mvv_object_path as $mvv_object) {
+                                $tree_id = $mvv_object->id;
                                 $mvv_object_id = $mvv_object instanceof StgteilabschnittModul
                                         ? $mvv_object->modul_id
                                         : $mvv_object->id;