title: Cannot resolve Symbol ObjectStateManager
body: <p>I have getting an Error of "<em>Cannot Resolve Symbol ObjectStateManager</em>" when trying to call it on my Database context from Entity Framework 4. I can't find anyone else having this issue. I have tried using <strong>System.Data</strong> and <strong>System.Data.Objects</strong>.</p>
  
  <p>Is there a specific Entity Framework that needs to be made in order to use the ObjectStateManager? Or Am I missing some sort of install package? I am using Database First Entity Framework.</p>
  
  <p>Here is the code it is giving my error: (Line 7)</p>
  
  <pre><code>[HttpPost]
          public ActionResult EditProfile(User user)
          {
              if (ModelState.IsValid)
              {
                  db.Users.Attach(user);
                  db.ObjectStateManager.ChangeObjectState(user, EntityState.Modified);
                  db.SaveChanges();
              }
              return RedirectToAction("Profile");
          }
  </code></pre>