Fatal error: Uncaught Error: Interface 'Symfony\Component\Serializer\Normalizer\DenormalizableInterface' not found in /home/gmcguire/public_html/concrete5/concrete/src/Board/Instance/Slot/Content/ObjectInterface.php:8 Stack trace: #0 {main} thrown in /home/gmcguire/public_html/concrete5/concrete/src/Board/Instance/Slot/Content/ObjectInterface.php on line 8