Fatal error: Uncaught Error: Class "Symfony\Component\Validator\Constraint" not found in I:\www\frameworks\Symfony\doctrine\vendor\symfony\doctrine-bridge\Validator\Constraints\UniqueEntity.php:25 Stack trace: #0 {main} thrown in I:\www\frameworks\Symfony\doctrine\vendor\symfony\doctrine-bridge\Validator\Constraints\UniqueEntity.php on line 25