Fatal error: Uncaught Error: Class 'Symfony\Component\Serializer\Normalizer\AbstractNormalizer' not found in D:\workspaces\liZiPingBack\vendor\symfony\serializer\Normalizer\JsonSerializableNormalizer.php:22 Stack trace: #0 {main} thrown in D:\workspaces\liZiPingBack\vendor\symfony\serializer\Normalizer\JsonSerializableNormalizer.php on line 22