Fatal error: Uncaught Error: Interface "Symfony\Component\Validator\ConstraintViolationListInterface" not found in C:\Apache24\htdocs\cms_upgrade\vendor\symfony\validator\ConstraintViolationList.php:19 Stack trace: #0 {main} thrown in C:\Apache24\htdocs\cms_upgrade\vendor\symfony\validator\ConstraintViolationList.php on line 19