Fatal error: Uncaught Error: Interface "MediaWiki\Deferred\DeferrableUpdate" not found in /var/www/html/extensions/FlaggedRevs/includes/backend/FRExtraCacheUpdate.php:15 Stack trace: #0 {main} thrown in /var/www/html/extensions/FlaggedRevs/includes/backend/FRExtraCacheUpdate.php on line 15