Fatal error: Uncaught Error: Interface "Symfony\Component\Form\FormInterface" not found in /home/marcgron/www/SSA/v2/vendor/symfony/form/Flow/FormFlowInterface.php:21 Stack trace: #0 {main} thrown in /home/marcgron/www/SSA/v2/vendor/symfony/form/Flow/FormFlowInterface.php on line 21