Unsupported media type

[fyher]

i test with this tutorial : http://besim.pl

In the function hello i have :

return sprintf('Hello %s!', $name);

and i have this response :

[exception] 415 | Unsupported Media Type | Symfony\Component\HttpKernel\Exception\UnsupportedMediaTypeHttpException
[message] Format 'soap' not supported, handler must be implemented