title: Mapping and metadata information could not be found for EntityType /Custom model
body: <p>I'm trying to create a custom model for registration and want it to save all the form info into database. It worked when i used User model but User model is auto generated model and i don't want to rewrite it every time i decide to make changes. So now when i did this custom Register model inherit from User model i getting this error when i try to register new user. </p>
  
  <p>here is my Register model:</p>
  
  <pre><code>using System;
  using System.Collections.Generic;
  using System.ComponentModel.DataAnnotations;
  using System.ComponentModel.DataAnnotations.Schema;
  using System.Linq;
  using System.Web;
  using CreckJackMVC;
  
  namespace CreckJackMVC.Models
  {
  
  public  class Register : User
  {
      [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]//Important for auto User Increment
      new public decimal cj_user_id { get; protected set; }
  
  
      [Required(ErrorMessage = "please provide full name", AllowEmptyStrings = false)]
      new public string cj_user_name { get; set; }
  
      [Required(ErrorMessage = "please provide your email", AllowEmptyStrings = false)]
      [RegularExpression(@"^([0-9a-zA-Z]([\+\-_\.][0-9a-zA-Z]+)*)+@(([0-9a-zA-Z][-\w]*[0-9a-zA-Z]*\.)+[a-zA-Z0-9]{2,3})$",
                  ErrorMessage = "please enter valid email")]
      new public string email { get; set; }
  
      [Required(ErrorMessage = "please provide password", AllowEmptyStrings = false)]
      [DataType(System.ComponentModel.DataAnnotations.DataType.Password)]
      [StringLength(50, MinimumLength = 8, ErrorMessage = "password must be 8 char long")]
      new public string user_pass { get; set; }
  
      [System.Web.Mvc.CompareAttribute("user_pass", ErrorMessage = "confirm password does not match")]
      [DataType(System.ComponentModel.DataAnnotations.DataType.Password)]
      new public string confirm_user_pass { get; set; }
  
  }
  }
  </code></pre>
  
  <p>here is my Controller: </p>
  
  <pre><code>public ActionResult Register(CreckJackMVC.Models.Register U)
      {
          if (ModelState.IsValid)
          {
              using (CreckJackLiveEntities dc = new CreckJackLiveEntities())
              {
  
                  //you should check duplicate registration here 
                  dc.Users.Add(U);
                  dc.SaveChanges();
                  ModelState.Clear();
                  U = null;
                  ViewBag.Message = "Registration successful! Welcome to CreakJack! ";
              }
          }
          return View(U);
      }
  </code></pre>
  
  <p>here is error msg: 
  <img src="https://i.stack.imgur.com/xqyQQ.png" alt="enter image description here"></p>