Fatal error: Uncaught Error: Class "Symfony\Component\HttpKernel\Event\FilterResponseEvent" not found in C:\Apache24\htdocs\cms_upgrade\vendor\symfony\http-kernel\Event\ResponseEvent.php:25 Stack trace: #0 {main} thrown in C:\Apache24\htdocs\cms_upgrade\vendor\symfony\http-kernel\Event\ResponseEvent.php on line 25