Fatal error: Uncaught Error: Class 'Symfony\Component\HttpFoundation\Session\Attribute\AttributeBag' not found in /home/optinadmin/rfl.optin.co.nz/concrete/vendor/symfony/http-foundation/Symfony/Component/HttpFoundation/Session/Attribute/NamespacedAttributeBag.php:20 Stack trace: #0 {main} thrown in /home/optinadmin/rfl.optin.co.nz/concrete/vendor/symfony/http-foundation/Symfony/Component/HttpFoundation/Session/Attribute/NamespacedAttributeBag.php on line 20