Fatal error: Uncaught Error: Interface "ILIAS\Survey\Mode\UIModifier" not found in /var/www/html/ilias/components/ILIAS/Survey/Mode/class.AbstractUIModifier.php:32 Stack trace: #0 {main} thrown in /var/www/html/ilias/components/ILIAS/Survey/Mode/class.AbstractUIModifier.php on line 32