Problem parsing error response

When a request has a parameter that does not have the right type, the server returns an error of type string and the client is not able to parse the error.

**Why?**
Seems like the error is returned as code BadRequest and in my app I already have a BadRequest that is of type object and not string.
This means that the error generated by the server about the type being wrong will throw an exception in the client since my bad request is an object and not just a string.

Am I doing something wrong here?