Fatal error: Uncaught Error: Interface "ILIAS\FileDelivery\Token\Serializer\Serializer" not found in /var/www/html/ilias/components/ILIAS/FileDelivery/src/Token/Serializer/PHPSerializer.php:26 Stack trace: #0 {main} thrown in /var/www/html/ilias/components/ILIAS/FileDelivery/src/Token/Serializer/PHPSerializer.php on line 26