Fatal error: Uncaught Error: Interface "Symfony\Component\Form\FormExtensionInterface" not found in I:\www\frameworks\Symfony\doctrine\vendor\symfony\form\Extension\DependencyInjection\DependencyInjectionExtension.php:19 Stack trace: #0 {main} thrown in I:\www\frameworks\Symfony\doctrine\vendor\symfony\form\Extension\DependencyInjection\DependencyInjectionExtension.php on line 19