Fatal error: Uncaught Error: Class "Symfony\Contracts\EventDispatcher\Event" not found in /usr/www/unityweb/public/hms/vendor/symfony/http-kernel/Event/KernelEvent.php:23 Stack trace: #0 {main} thrown in /usr/www/unityweb/public/hms/vendor/symfony/http-kernel/Event/KernelEvent.php on line 23