Fatal error: Uncaught Error: Interface 'Symfony\Component\Validator\ConstraintValidatorInterface' not found in /home/devmecseminars/public_html/mec/vendor/symfony/validator/ConstraintValidator.php:21 Stack trace: #0 {main} thrown in /home/devmecseminars/public_html/mec/vendor/symfony/validator/ConstraintValidator.php on line 21