Fatal error: Uncaught Error: Interface "Psr\EventDispatcher\StoppableEventInterface" not found in D:\Apache24\www\trace\新建文件夹\Backstage\vendor\symfony\event-dispatcher-contracts\Event.php:31 Stack trace: #0 {main} thrown in D:\Apache24\www\trace\新建文件夹\Backstage\vendor\symfony\event-dispatcher-contracts\Event.php on line 31