Fatal error: Uncaught Error: Class "Symfony\Component\Validator\ConstraintValidator" not found in C:\Apache24\htdocs\cms_upgrade\vendor\symfony\validator\Constraints\CountryValidator.php:26 Stack trace: #0 {main} thrown in C:\Apache24\htdocs\cms_upgrade\vendor\symfony\validator\Constraints\CountryValidator.php on line 26