Fatal error: Uncaught Error: Class 'Symfony\Component\Serializer\Normalizer\AbstractNormalizer' not found in C:\SistemasPHP\observatorio4\vendor\symfony\serializer\Normalizer\JsonSerializableNormalizer.php:22 Stack trace: #0 {main} thrown in C:\SistemasPHP\observatorio4\vendor\symfony\serializer\Normalizer\JsonSerializableNormalizer.php on line 22