Fatal error: Uncaught Error: Class 'Symfony\Contracts\EventDispatcher\Event' not found in D:\xampp7\htdocs\www\nbkm\show_ir\vendor\symfony\event-dispatcher\GenericEvent.php:23 Stack trace: #0 {main} thrown in D:\xampp7\htdocs\www\nbkm\show_ir\vendor\symfony\event-dispatcher\GenericEvent.php on line 23