Fatal error: Uncaught Error: Interface 'Psr\EventDispatcher\StoppableEventInterface' not found in D:\xampp\htdocs\psp\backend\vendor\symfony\event-dispatcher-contracts\Event.php:31
Stack trace:
#0 {main}
thrown in D:\xampp\htdocs\psp\backend\vendor\symfony\event-dispatcher-contracts\Event.php on line 31