Fatal error: Uncaught Error: Interface "ILIAS\MetaData\OERExposer\OAIPMH\Responses\WriterInterface" not found in /var/www/html/ilias/components/ILIAS/MetaData/classes/OERExposer/OAIPMH/Responses/NullWriter.php:27 Stack trace: #0 {main} thrown in /var/www/html/ilias/components/ILIAS/MetaData/classes/OERExposer/OAIPMH/Responses/NullWriter.php on line 27