Processing of the HTTP request resulted in an exception. Please see the HTTP response returned by...

Processing of the HTTP request resulted in an exception. Please see the HTTP response returned by the 'Response' property of this exception for details.

var resp = new HttpResponseMessage(HttpStatusCode.NotFound)
                {
                    Content = new StringContent(JsonConvert.SerializeObject("Code has been not found"), Encoding.UTF8, "application/json"),
                    ReasonPhrase = "Code Not Found",
                };
throw new HttpResponseException(resp);