Fatal error: Uncaught Error: Interface 'Symfony\Component\EventDispatcher\EventDispatcherInterface' not found in /home/devmecseminars/public_html/mec/vendor/symfony/event-dispatcher/EventDispatcher.php:33 Stack trace: #0 {main} thrown in /home/devmecseminars/public_html/mec/vendor/symfony/event-dispatcher/EventDispatcher.php on line 33