Fatal error: Uncaught Error: Interface "Symfony\Contracts\EventDispatcher\EventDispatcherInterface" not found in D:\Apache24\www\gin_gs1\backstage\vendor\symfony\event-dispatcher\EventDispatcherInterface.php:23 Stack trace: #0 {main} thrown in D:\Apache24\www\gin_gs1\backstage\vendor\symfony\event-dispatcher\EventDispatcherInterface.php on line 23