Fatal error: Uncaught Error: Interface "ILIAS\UI\Component\Tree\TreeRecursion" not found in /var/www/html/ilias/components/ILIAS/Style/System/classes/Provider/KSDocumentationTreeRecursion.php:28 Stack trace: #0 {main} thrown in /var/www/html/ilias/components/ILIAS/Style/System/classes/Provider/KSDocumentationTreeRecursion.php on line 28