ASP.NET MVC3 Validation Type Names Error

Question

I get the following error:

    Validation type names in unobtrusive client validation rules must be unique. The following validation type was seen more than once: required

I have no idea why, I have read some stuff about custom validation and ninject, but I don't think it is that.

I am creating a custom account management system where administrators can create/edit users. I'm using the ASP.NET Membership, Role, Profile . When you create a new application with Internet ticked it creates all that account stuff. All I tried to do was reuse the RegisterModel that is provided with that in my AccountManagement Area . But then the error started to appear, I don't have any custom validation providers or anything. The error/exception also appears in Account Views as well (the ones created by the MVC template).

The error happens on this line of the view:

<div class="editor-label">
    @Html.LabelFor(model => model.User.UserName)
</div>
<div class="editor-field">
    @Html.TextBoxFor(model => model.User.UserName) <!-- THIS LINE -->
    @Html.ValidationMessageFor(model => model.User.UserName)
</div>

My Model is a ViewModel class with a property:

public RegisterModel User {get;set;}

I have wrote this entire website with no problems in the way I do anything apart from when it came to just reusing RegisterModel . Since then I have tried creating a completely new Model called NewUserModel and referencing that solely in the Area to no avail.

I use the DependencyResolver to use Ninject as my IoC/DI. I can't imagine that to be a problem....

Model:

namespace MyApplication.Areas.AccountManagement.Models
{
    using System;
    using System.Collections.Generic;
    using System.ComponentModel.DataAnnotations;
    using System.Linq;
    using System.Web;

    public class NewUserModel
    {
        [Required]
        [Display(Name = "User name")]
        public string UserName { get; set; }

        [Required]
        [Display(Name = "First Name")]
        public string FirstName { get; set; }

        [Required]
        [Display(Name = "Last Name")]
        public string LastName { get; set; }

        [Required, RegularExpression(@"[0-9]{8}", ErrorMessage = "Please enter in an 8 digit Intel Worldwide Id")]
        [Display(Name = "WWID")]
        public string WWID { get; set; }

        [Required]
        [DataType(DataType.EmailAddress)]
        [Display(Name = "Email address")]
        public string Email { get; set; }

        [Required]
        [StringLength(100, ErrorMessage = "The {0} must be at least {2} characters long.", MinimumLength = 6)]
        [DataType(DataType.Password)]
        [Display(Name = "Password")]
        public string Password { get; set; }

        [DataType(DataType.Password)]
        [Display(Name = "Confirm password")]
        [System.Web.Mvc.Compare("Password", ErrorMessage = "The password and confirmation password do not match.")]
        public string ConfirmPassword { get; set; }
    }
}

Answer 1

Usually this type of problem occurs if more than one validation rule is applied to a property. Can you check the followings:

1. Find and check all the reference to the NewUserModel if any other custom validator is validating the model.
2. Check what your NewUserModel is inheriting/implementing

Answer 2

This error came about because of having Ninject.MVC3 added from nuget to the project.

It is something to do with how Ninject injects validation or that is the best answer I could find online!

I removed Ninject entirely from my application, then re-added Ninject (the normal one) and everything works fine!!