Fatal error: Uncaught Error: Class "ilAdvancedMDFieldDefinition" not found in /var/www/html/ilias/components/ILIAS/AdvancedMetaData/classes/Types/class.ilAdvancedMDFieldDefinitionExternalLink.php:11 Stack trace: #0 {main} thrown in /var/www/html/ilias/components/ILIAS/AdvancedMetaData/classes/Types/class.ilAdvancedMDFieldDefinitionExternalLink.php on line 11