Fatal error: Uncaught Error: Interface 'Symfony\Component\EventDispatcher\EventSubscriberInterface' not found in /var/www/html/tmp/contrib/cer/src/EventSubscriber/CerSubscriber.php:10 Stack trace: #0 {main} thrown in /var/www/html/tmp/contrib/cer/src/EventSubscriber/CerSubscriber.php on line 10