Fatal error: Uncaught Error: Class 'Symfony\Component\EventDispatcher\EventDispatcher' not found in /home/app/htdocs/ninja/vendor/symfony/event-dispatcher/ContainerAwareEventDispatcher.php:24 Stack trace: #0 {main} thrown in /home/app/htdocs/ninja/vendor/symfony/event-dispatcher/ContainerAwareEventDispatcher.php on line 24