Fatal error: Uncaught Error: Class 'Symfony\Component\HttpFoundation\Session\Storage\Handler\AbstractSessionHandler' not found in /mnt/volume_lon1_01/backend/admin/vendor/symfony/http-foundation/Session/Storage/Handler/PdoSessionHandler.php:41 Stack trace: #0 {main} thrown in /mnt/volume_lon1_01/backend/admin/vendor/symfony/http-foundation/Session/Storage/Handler/PdoSessionHandler.php on line 41