Fatal error: Uncaught Error: Class 'Symfony\Component\Serializer\Normalizer\AbstractObjectNormalizer' not found in /home/devmecseminars/public_html/mec/vendor/symfony/serializer/Normalizer/ObjectNormalizer.php:29 Stack trace: #0 {main} thrown in /home/devmecseminars/public_html/mec/vendor/symfony/serializer/Normalizer/ObjectNormalizer.php on line 29