Fatal error: Uncaught Error: Class 'Symfony\Component\HttpKernel\Event\KernelEvent' not found in D:\workspaces\liZiPingBack\vendor\symfony\http-kernel\Event\GetResponseEvent.php:19 Stack trace: #0 {main} thrown in D:\workspaces\liZiPingBack\vendor\symfony\http-kernel\Event\GetResponseEvent.php on line 19