Fatal error: Uncaught Error: Class 'Symfony\Component\Form\AbstractExtension' not found in C:\xampp\htdocs\plugins\Symfony\Component\Form\Extension\HttpFoundation\HttpFoundationExtension.php:21 Stack trace: #0 {main} thrown in C:\xampp\htdocs\plugins\Symfony\Component\Form\Extension\HttpFoundation\HttpFoundationExtension.php on line 21