Fatal error: Uncaught Error: Class "Symfony\Component\Serializer\Exception\UnexpectedValueException" not found in /media/jean/learning/huagai/drupal/vendor/symfony/serializer/Exception/NotEncodableValueException.php:17 Stack trace: #0 {main} thrown in /media/jean/learning/huagai/drupal/vendor/symfony/serializer/Exception/NotEncodableValueException.php on line 17