Fatal error: Uncaught Error: Class 'Symfony\Component\HttpFoundation\Session\Attribute\AttributeBag' not found in /home/benjamincb/demos/acdg-site/vendor/contao/core-bundle/src/Session/Attribute/ArrayAttributeBag.php:22 Stack trace: #0 {main} thrown in /home/benjamincb/demos/acdg-site/vendor/contao/core-bundle/src/Session/Attribute/ArrayAttributeBag.php on line 22