Fatal error: Uncaught Error: Interface "ILIAS\UI\Component\Signal" not found in /var/www/html/ilias/components/ILIAS/UI/src/Component/ReplaceContentSignal.php:30 Stack trace: #0 {main} thrown in /var/www/html/ilias/components/ILIAS/UI/src/Component/ReplaceContentSignal.php on line 30