Fatal error: Uncaught Error: Interface "Symfony\Component\Serializer\Normalizer\DenormalizableInterface" not found in /srv/disk1/2895578/www/whittonphotographicclub.org.uk/concrete/src/Summary/Data/Collection.php:14 Stack trace: #0 {main} thrown in /srv/disk1/2895578/www/whittonphotographicclub.org.uk/concrete/src/Summary/Data/Collection.php on line 14