Fatal error: Uncaught Error: Class 'Symfony\Component\Form\AbstractType' not found in /home/lafaamicps/www/symfony/vendor/sonata-project/admin-bundle/Form/Type/ModelReferenceType.php:28 Stack trace: #0 {main} thrown in /home/lafaamicps/www/symfony/vendor/sonata-project/admin-bundle/Form/Type/ModelReferenceType.php on line 28