Apicontroller return HTTP Error 404.3 - Not Found

Question

I got a simple class inheriting from apicontroller.

The class code is the following:

 public HttpResponseMessage Post(StatusUpdate statusUpdate)
        {
            //string url = statusUpdate.File.Url.ToString();
            return Request.CreateResponse(HttpStatusCode.Created);
        }

I wrote another application to trigger the service. When I run it via visual studio I manage to get a response. However, when I deploy the above mentioned project on IIS, I get an http error 404.3 - Not found.

Any clues?