Fatal error: Uncaught Error: Class "Symfony\Component\HttpKernel\Event\KernelEvent" not found in /srv/www/sites/public/starter-cms/vendor/symfony/http-kernel/Event/ControllerEvent.php:28 Stack trace: #0 {main} thrown in /srv/www/sites/public/starter-cms/vendor/symfony/http-kernel/Event/ControllerEvent.php on line 28