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