Fatal error: Uncaught Error: Interface "ilObjectProperty" not found in /var/www/html/ilias/components/ILIAS/ILIASObject/classes/Properties/ObjectReferenceProperties/ObjectAvailabilityPeriodProperty.php:32 Stack trace: #0 {main} thrown in /var/www/html/ilias/components/ILIAS/ILIASObject/classes/Properties/ObjectReferenceProperties/ObjectAvailabilityPeriodProperty.php on line 32