Fatal error: Uncaught Error: Interface "ilAppEventListener" not found in /var/www/html/ilias/components/ILIAS/Certificate/classes/class.ilCertificateAppEventListener.php:25 Stack trace: #0 {main} thrown in /var/www/html/ilias/components/ILIAS/Certificate/classes/class.ilCertificateAppEventListener.php on line 25