Fatal error: Uncaught Error: Interface "Symfony\Component\HttpFoundation\Session\SessionBagInterface" not found in C:\xampp\htdocs\mflux\vendor\symfony\http-foundation\Session\Flash\FlashBagInterface.php:21 Stack trace: #0 {main} thrown in C:\xampp\htdocs\mflux\vendor\symfony\http-foundation\Session\Flash\FlashBagInterface.php on line 21