Fatal error: Uncaught Error: Class "Symfony\Component\EventDispatcher\EventDispatcher" not found in D:\Application\www\Training\vendor\symfony\http-kernel\Tests\Fixtures\TestEventDispatcher.php:17 Stack trace: #0 {main} thrown in D:\Application\www\Training\vendor\symfony\http-kernel\Tests\Fixtures\TestEventDispatcher.php on line 17