Fatal error: Uncaught Error: Class "ILIAS\Setup\Agent\NullAgent" not found in /var/www/html/ilias/components/ILIAS/Course/Setup/ilCourseSetupAgent.php:28 Stack trace: #0 {main} thrown in /var/www/html/ilias/components/ILIAS/Course/Setup/ilCourseSetupAgent.php on line 28