Fatal error: Uncaught Error: Class 'Symfony\Component\Serializer\Exception\InvalidArgumentException' not found in /home/optinadmin/rfl.optin.co.nz/concrete/vendor/symfony/serializer/Symfony/Component/Serializer/Exception/UnsupportedException.php:19 Stack trace: #0 {main} thrown in /home/optinadmin/rfl.optin.co.nz/concrete/vendor/symfony/serializer/Symfony/Component/Serializer/Exception/UnsupportedException.php on line 19