Fatal error: Uncaught Error: Class "Symfony\Component\Validator\Mapping\Loader\AbstractLoader" not found in I:\www\frameworks\Symfony\doctrine\vendor\symfony\validator\Mapping\Loader\FileLoader.php:24 Stack trace: #0 {main} thrown in I:\www\frameworks\Symfony\doctrine\vendor\symfony\validator\Mapping\Loader\FileLoader.php on line 24