Fatal error: Uncaught Error: Class "Symfony\Component\Validator\Constraint" not found in /home/renatori/harmoniflor.com.br/vendor/symfony/validator/Constraints/Issn.php:26 Stack trace: #0 {main} thrown in /home/renatori/harmoniflor.com.br/vendor/symfony/validator/Constraints/Issn.php on line 26