Fatal error: Uncaught Error: Interface "MediaWiki\Notification\NotificationHandler" not found in /usr/www/otte/public/sphunt1/extensions/Echo/includes/EchoNotificationHandler.php:14 Stack trace: #0 {main} thrown in /usr/www/otte/public/sphunt1/extensions/Echo/includes/EchoNotificationHandler.php on line 14