Fatal error: Uncaught Error: Class "Symfony\Component\Form\AbstractType" not found in /home/ntpcbgtpp/public_html/mat1/src/Form/Type/TriStateCheckboxType.php:34 Stack trace: #0 {main} thrown in /home/ntpcbgtpp/public_html/mat1/src/Form/Type/TriStateCheckboxType.php on line 34