Fatal error: Uncaught Error: Class 'Symfony\Component\Serializer\Exception\RuntimeException' not found in /home/devmecseminars/public_html/mec/vendor/symfony/serializer/Exception/ExtraAttributesException.php:19 Stack trace: #0 {main} thrown in /home/devmecseminars/public_html/mec/vendor/symfony/serializer/Exception/ExtraAttributesException.php on line 19