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