Fatal error: Uncaught Error: Class "Symfony\Component\Serializer\Normalizer\AbstractNormalizer" not found in I:\www\frameworks\Symfony\doctrine\vendor\symfony\serializer\Normalizer\JsonSerializableNormalizer.php:22 Stack trace: #0 {main} thrown in I:\www\frameworks\Symfony\doctrine\vendor\symfony\serializer\Normalizer\JsonSerializableNormalizer.php on line 22