Fatal error: Uncaught Error: Class "Symfony\Contracts\EventDispatcher\Event" not found in I:\www\frameworks\Symfony\doctrine\vendor\symfony\security-http\Event\AuthenticationTokenCreatedEvent.php:24 Stack trace: #0 {main} thrown in I:\www\frameworks\Symfony\doctrine\vendor\symfony\security-http\Event\AuthenticationTokenCreatedEvent.php on line 24