diff --git a/components/ILIAS/CategoryReference/classes/class.ilObjCategoryReferenceListGUI.php b/components/ILIAS/CategoryReference/classes/class.ilObjCategoryReferenceListGUI.php
index a134814408eb..276b038401ec 100755
--- a/components/ILIAS/CategoryReference/classes/class.ilObjCategoryReferenceListGUI.php
+++ b/components/ILIAS/CategoryReference/classes/class.ilObjCategoryReferenceListGUI.php
@@ -71,7 +71,7 @@ public function init(): void
         $this->subscribe_enabled = true;
         $this->link_enabled = false;
         $this->info_screen_enabled = true;
-        $this->type = 'catr';
+        $this->type = 'cat';
         $this->gui_class_name = "ilobjcategorygui";
 
         $this->substitutions = ilAdvancedMDSubstitution::_getInstanceByObjectType($this->type);
diff --git a/components/ILIAS/Course/classes/class.ilObjCourseListGUI.php b/components/ILIAS/Course/classes/class.ilObjCourseListGUI.php
index 0d8460738bed..b4e7d0306978 100755
--- a/components/ILIAS/Course/classes/class.ilObjCourseListGUI.php
+++ b/components/ILIAS/Course/classes/class.ilObjCourseListGUI.php
@@ -178,7 +178,6 @@ public function checkCommandAccess(
         }
 
         if ($permission == 'crs_linked') {
-            $type = ilObject::_lookupType($ref_id, true);
             return
                 parent::checkCommandAccess('read', $cmd, $ref_id, $type, $obj_id) ||
                 parent::checkCommandAccess('join', $cmd, $ref_id, $type, $obj_id);
diff --git a/components/ILIAS/CourseReference/classes/class.ilObjCourseReferenceListGUI.php b/components/ILIAS/CourseReference/classes/class.ilObjCourseReferenceListGUI.php
index 3d5dd4943307..5a76954b5a9a 100755
--- a/components/ILIAS/CourseReference/classes/class.ilObjCourseReferenceListGUI.php
+++ b/components/ILIAS/CourseReference/classes/class.ilObjCourseReferenceListGUI.php
@@ -78,7 +78,7 @@ public function init(): void
         $this->subscribe_enabled = true;
         $this->link_enabled = false;
         $this->info_screen_enabled = true;
-        $this->type = 'crsr';
+        $this->type = 'crs';
         $this->gui_class_name = "ilobjcoursegui";
 
         $this->substitutions = ilAdvancedMDSubstitution::_getInstanceByObjectType($this->type);
diff --git a/components/ILIAS/Group/classes/class.ilObjGroupListGUI.php b/components/ILIAS/Group/classes/class.ilObjGroupListGUI.php
index 1fd16f823b04..7e7eb20072ac 100755
--- a/components/ILIAS/Group/classes/class.ilObjGroupListGUI.php
+++ b/components/ILIAS/Group/classes/class.ilObjGroupListGUI.php
@@ -159,7 +159,6 @@ public function checkCommandAccess(
         ?int $obj_id = null
     ): bool {
         if ($permission == 'grp_linked') {
-            $type = ilObject::_lookupType($ref_id, true);
             return
                 parent::checkCommandAccess('read', '', $ref_id, $type, $obj_id) ||
                 parent::checkCommandAccess('join', 'join', $ref_id, $type, $obj_id);
diff --git a/components/ILIAS/GroupReference/classes/class.ilObjGroupReferenceListGUI.php b/components/ILIAS/GroupReference/classes/class.ilObjGroupReferenceListGUI.php
index 938c61cdeaea..6f0abbd241c8 100755
--- a/components/ILIAS/GroupReference/classes/class.ilObjGroupReferenceListGUI.php
+++ b/components/ILIAS/GroupReference/classes/class.ilObjGroupReferenceListGUI.php
@@ -79,7 +79,7 @@ public function init(): void
         $this->subscribe_enabled = true;
         $this->link_enabled = false;
         $this->info_screen_enabled = true;
-        $this->type = 'grpr';
+        $this->type = 'grp';
         $this->gui_class_name = "ilobjgroupgui";
 
         $this->substitutions = ilAdvancedMDSubstitution::_getInstanceByObjectType($this->type);
diff --git a/components/ILIAS/StudyProgrammeReference/classes/class.ilObjStudyProgrammeReferenceListGUI.php b/components/ILIAS/StudyProgrammeReference/classes/class.ilObjStudyProgrammeReferenceListGUI.php
index f808fd9be3b7..fd2ec03c9a7b 100755
--- a/components/ILIAS/StudyProgrammeReference/classes/class.ilObjStudyProgrammeReferenceListGUI.php
+++ b/components/ILIAS/StudyProgrammeReference/classes/class.ilObjStudyProgrammeReferenceListGUI.php
@@ -75,7 +75,7 @@ public function init(): void
         $this->subscribe_enabled = false;
         $this->link_enabled = false;
 
-        $this->type = "prgr";
+        $this->type = "prg";
         $this->gui_class_name = "ilobjstudyprogrammegui";
 
         $this->substitutions = ilAdvancedMDSubstitution::_getInstanceByObjectType($this->type);