Fatal error: Uncaught Error: Class "Symfony\Component\EventDispatcher\Event" not found in /mnt/VenusReview/review/lyrasoft/dva/staging/vendor/symfony/event-dispatcher/GenericEvent.php:21 Stack trace: #0 {main} thrown in /mnt/VenusReview/review/lyrasoft/dva/staging/vendor/symfony/event-dispatcher/GenericEvent.php on line 21