Fatal error: Uncaught Error: Class "Symfony\Component\EventDispatcher\Event" not found in /opt/lampp/htdocs/myhospitalnow/mhn-hospital-ms/vendorback/symfony/event-dispatcher/GenericEvent.php:21 Stack trace: #0 {main} thrown in /opt/lampp/htdocs/myhospitalnow/mhn-hospital-ms/vendorback/symfony/event-dispatcher/GenericEvent.php on line 21