Fatal error: Uncaught Error: Interface "Symfony\Component\Serializer\Normalizer\NormalizerInterface" not found in C:\Apache24\htdocs\cms_upgrade\vendor\symfony\serializer\Normalizer\ConstraintViolationListNormalizer.php:25 Stack trace: #0 {main} thrown in C:\Apache24\htdocs\cms_upgrade\vendor\symfony\serializer\Normalizer\ConstraintViolationListNormalizer.php on line 25