Fatal error: Uncaught Error: Interface 'Symfony\Contracts\EventDispatcher\EventDispatcherInterface' not found in /home/devmecseminars/public_html/mec/vendor/symfony/event-dispatcher/EventDispatcherInterface.php:23 Stack trace: #0 {main} thrown in /home/devmecseminars/public_html/mec/vendor/symfony/event-dispatcher/EventDispatcherInterface.php on line 23