Fatal error: Uncaught Error: Interface 'Symfony\Contracts\EventDispatcher\EventDispatcherInterface' not found in D:\xampp\htdocs\psp\backend\vendor\symfony\event-dispatcher\EventDispatcherInterface.php:23 Stack trace: #0 {main} thrown in D:\xampp\htdocs\psp\backend\vendor\symfony\event-dispatcher\EventDispatcherInterface.php on line 23