POST web api内部错误500

我的web api应用程序有一个问题。我得到一个内部错误500当我试图张贴(保存)一个新用户在我的数据库。下面的函数是我用来进行客户端调用的函数。

public void InsertNewUser(RegisterModel pNewUser, string pEmail)
{
    // Build rest uri
    string lREST_Uri_Browse = string.Format(@"api/accountapi/saveuserdata"
    // User data
    /*pModelSerialized*/);
    // Complete URI
    string lREST_Uri = Helpers_API.endPoint + lREST_Uri_Browse;
    var client = new HttpClient();
    client.BaseAddress = new Uri(Helpers_API.endPoint);
        var newUser = new Models.Models_API.Users
        {
            Email = pNewUser.Email,
            FName = pNewUser.FName,
            LName = pNewUser.LName,
            Inserted = DateTime.Now,
            ActiveAcc = true,
            AccType = pNewUser.AccType,
            BCompanyID = pNewUser.CompanyID,
            PID = pNewUser.PID,
            Password = pNewUser.Password,
            Token = GetToken(pEmail),
            ThirdParty = 0,
            Gender = pNewUser.Gender,
            BirthDate = pNewUser.BirthDate
        };
        // Add an Accept header for JSON format.
        //client.DefaultRequestHeaders.Accept.Add(
        //    new MediaTypeWithQualityHeaderValue("application/json"));
        // Create the JSON formatter.
        MediaTypeFormatter jsonFormatter = new JsonMediaTypeFormatter();
        // Use the JSON formatter to create the content of the request body.
        HttpContent content = new ObjectContent<Models.Models_API.Users>(newUser, jsonFormatter);
        var result = client.PostAsync(lREST_Uri_Browse, content).Result;
}

这是模型

public class Users
{
    public int BrokerID { get; set; }
    public DateTime Inserted { get; set; }
    public string Email { get; set; }
    public string FName { get; set; }
    public string LName { get; set; }
    public bool ActiveAcc { get; set; }
    public int BCompanyID { get; set; }
    public int PID { get; set; }
    public int AccType { get; set; }
    public string Password { get; set; }
    public string Token { get; set; }
    public int Gender { get; set; }
    public DateTime BirthDate { get; set; }
    public int ThirdParty { get; set; }
}

下面是APIController中的POST:

public HttpResponseMessage SaveUserData(Users pNewUser)
    {
        bool createUser = false;
        // First check for provided email in DB
        Users existingUser = asigCtx.Users.Where(u => u.Email == pNewUser.Email).SingleOrDefault();
        if (existingUser == null)
            createUser = true;
        else if (existingUser.ActiveAcc)
            createUser = true;
        if (createUser)
        {
            using (asigCtx = new AsigPrimeContext())
            {
                Users user = new Users()
                {
                    Email = pNewUser.Email,
                    FName = pNewUser.FName,
                    LName = pNewUser.LName,
                    Inserted = DateTime.Now,
                    ActiveAcc = true,
                    AccType = pNewUser.AccType,
                    BCompanyID = pNewUser.BCompanyID,
                    PID = pNewUser.PID,
                    Password = pNewUser.Password,
                    Token = pNewUser.Token,
                    ThirdParty = 0,
                    Gender = pNewUser.Gender,
                    BirthDate = pNewUser.BirthDate,
                };
                asigCtx.Users.Add(user);
                asigCtx.SaveChanges();
            }
        }
        var response = Request.CreateResponse<Users>(HttpStatusCode.Created, pNewUser);
        return response;
    }

谁能给我的建议与这段代码，因为我是新的，我只是想做它的赖特。TNX