Fatal error: Uncaught Error: Class "ilContainerReference" not found in /var/www/html/ilias/components/ILIAS/CategoryReference/classes/class.ilObjCategoryReference.php:24 Stack trace: #0 {main} thrown in /var/www/html/ilias/components/ILIAS/CategoryReference/classes/class.ilObjCategoryReference.php on line 24