Fatal error: Uncaught Error: Interface "MediaWiki\Diff\Hook\DifferenceEngineViewHeaderHook" not found in /var/www/html/w/extensions/Wikibase/repo/includes/Hooks/DifferenceEngineViewHeaderHookHandler.php:18 Stack trace: #0 {main} thrown in /var/www/html/w/extensions/Wikibase/repo/includes/Hooks/DifferenceEngineViewHeaderHookHandler.php on line 18