title: EntityType 'MyProfile' has no key defined. Define the key for this EntityType
body: <p>I am not sure why I am getting this error message.  I have a primary key defined in my sql database for it.  Here is my code:</p>
  
  <pre><code>[HttpPost]
      public ActionResult Register(RegisterModel model)
      {
          if (ModelState.IsValid)
          {
              // Attempt to register the user
              MembershipCreateStatus createStatus = MembershipService.CreateUser(model.UserName, model.Password, model.Email);
  
              if (createStatus == MembershipCreateStatus.Success)
              {
  
                  FormsService.SignIn(model.UserName, false /* createPersistentCookie */);
                  MembershipUser myObject = Membership.GetUser();
                  Guid UserID = (Guid)myObject.ProviderUserKey;
                  MyProfile profile = new MyProfile();
                  profile.Address = model.Address;
                  profile.City = model.City;
                  profile.Zip = model.Zip;
                  profile.State = model.State;
                  profile.UserId = UserID;
                  db.Profiles.Add(profile);
                  return RedirectToAction("Index", "Home");
              }
              else
              {
                  ModelState.AddModelError("", AccountValidation.ErrorCodeToString(createStatus));
              }
          }
  
          // If we got this far, something failed, redisplay form
          ViewBag.PasswordLength = MembershipService.MinPasswordLength;
          return View(model);
      }
  </code></pre>
  
  <p>And this is my MyProfile Class:</p>
  
  <pre><code>   namespace MatchGaming.Models
  {
      [Bind(Exclude = "ProfileId")]
      public class MyProfile
      {
          [ScaffoldColumn(false)]
          public int ProfileId { get; set; }
  
          public Guid UserId { get; set; }
  
          [DisplayName("Address")]
          public string Address { get; set; }
  
          [DisplayName("City")]
          public string City { get; set; }
  
          [DisplayName("Zip")]
          public string Zip { get; set; }
  
          [DisplayName("State")]
          public string State { get; set; }
  
  
      }
  }
  </code></pre>
  
  <p>I am not sure why I am getting this error: <code>EntityType 'MyProfile' has no key defined. Define the key for this EntityType.</code> when it tries to add to the database <code>db.Profiles.Add(profile);</code>.  </p>