Fatal error: Uncaught Error: Class "SMW\MediaWiki\Specials\Admin\TaskHandler" not found in /var/www/html/extensions/SemanticMediaWiki/src/MediaWiki/Specials/Admin/Alerts/ByNamespaceInvalidEntitiesMaintenanceAlertTaskHandler.php:18 Stack trace: #0 {main} thrown in /var/www/html/extensions/SemanticMediaWiki/src/MediaWiki/Specials/Admin/Alerts/ByNamespaceInvalidEntitiesMaintenanceAlertTaskHandler.php on line 18