Fatal error: Uncaught Error: Interface "Symfony\Component\EventDispatcher\EventSubscriberInterface" not found in /usr/local/www/dctalk/data/forum/ext/paul999/ajaxshoutbox/event/shoutbox_listener.php:12 Stack trace: #0 {main} thrown in /usr/local/www/dctalk/data/forum/ext/paul999/ajaxshoutbox/event/shoutbox_listener.php on line 12