public HttpResponseMessage AddUser([FromBody] User value, [FromUri] int userId) { var re = Request; var headers = re.Headers; if (headers.Contains("userId")) { string token = headers.GetValues("userId").First(); } if (ModelState.IsValid) { return((LogicUser.AddUser(value, userId)) ? new HttpResponseMessage(HttpStatusCode.Created) : new HttpResponseMessage(HttpStatusCode.BadRequest) { Content = new ObjectContent <String>("Can not add to DB", new JsonMediaTypeFormatter()) }); } ; List <string> ErrorList = new List <string>(); //if the code reached this part - the user is not valid foreach (var item in ModelState.Values) { foreach (var err in item.Errors) { ErrorList.Add(err.ErrorMessage); } } return(new HttpResponseMessage(HttpStatusCode.BadRequest) { Content = new ObjectContent <List <string> >(ErrorList, new JsonMediaTypeFormatter()) }); }