Fatal error: Uncaught Error: Class "Doctrine\DBAL\Exception\ConstraintViolationException" not found in E:\xampp\htdocs\stms\vendor\doctrine\dbal\src\Exception\NotNullConstraintViolationException.php:10 Stack trace: #0 {main} thrown in E:\xampp\htdocs\stms\vendor\doctrine\dbal\src\Exception\NotNullConstraintViolationException.php on line 10