Fatal error: Uncaught Error: Interface "ILIAS\MetaData\Repository\IdentifierHandler\IdentifierHandlerInterface" not found in /var/www/html/ilias/components/ILIAS/MetaData/classes/Repository/IdentifierHandler/IdentifierHandler.php:30 Stack trace: #0 {main} thrown in /var/www/html/ilias/components/ILIAS/MetaData/classes/Repository/IdentifierHandler/IdentifierHandler.php on line 30