Fatal error: Uncaught Error: Class "Symfony\Component\HttpKernel\Event\KernelEvent" not found in D:\Apache24\www\qilu\back-end\vendor\symfony\http-kernel\Event\FinishRequestEvent.php:19 Stack trace: #0 {main} thrown in D:\Apache24\www\qilu\back-end\vendor\symfony\http-kernel\Event\FinishRequestEvent.php on line 19