Fatal error: Uncaught Error: Interface "Symfony\Component\EventDispatcher\EventSubscriberInterface" not found in /home/ondemand/test.ondemandpro.net/php-docs-samples/appengine/flexible/symfony/src/AppBundle/EventSubscriber/ExceptionSubscriber.php:12 Stack trace: #0 {main} thrown in /home/ondemand/test.ondemandpro.net/php-docs-samples/appengine/flexible/symfony/src/AppBundle/EventSubscriber/ExceptionSubscriber.php on line 12