EntitySqlException when trying to access DbUpdateConcurrencyException's GetDatabaseValues() entity - asp.net-mvc-3

Question

I'm trying to do the tutorial here: http://www.asp.net/entity-framework/tutorials/handling-concurrency-with-the-entity-framework-in-an-asp-net-mvc-application
In the ActionResult Edit, I have the following code:
public ActionResult Edit(Product product)
{
try
{
if (ModelState.IsValid)
{
db.Entry(product).State = EntityState.Modified;
db.SaveChanges();
return RedirectToAction("Index");
}
}
catch(DbUpdateConcurrencyException ex)
{
var entry = ex.Entries.Single();
var databaseValuesObj = entry.GetDatabaseValues().ToObject();
var databaseValues = (Product)databaseValuesObj;
var clientValues = (Product)entry.Entity;
if (databaseValues.Name != clientValues.Name)
ModelState.AddModelError("Name", "Current value: "
+ databaseValues.Name);
if (databaseValues.Description != clientValues.Description)
ModelState.AddModelError("Description", "Current value: "
+ String.Format("{0:c}", databaseValues.Description));
if (databaseValues.ControllingStudentId != clientValues.ControllingStudentId)
ModelState.AddModelError("ControllingStudentId", "Current value: "
+ String.Format("{0:d}", databaseValues.ControllingStudentId));
ModelState.AddModelError(string.Empty, "The record you attempted to edit "
+ "was modified by another user after you got the original value. The "
+ "edit operation was canceled and the current values in the database "
+ "have been displayed. If you still want to edit this record, click "
+ "the Save button again. Otherwise click the Back to List hyperlink.");
product.Timestamp = databaseValues.Timestamp;
}
catch (DataException)
{
//Log the error (add a variable name after Exception)
ModelState.AddModelError(string.Empty, "Unable to save changes. Try again, and if the problem persists contact your system administrator.");
}
return View(product);
}
On the var databaseValuesObj = entry.GetDatabaseValues().ToObject(); line, I get an exception like this:
System.Data.EntitySqlException was unhandled by user code
Message=Type 'MvcApplication3.DAL.Product' could not be found. Make sure that the required schemas are loaded and that the namespaces are imported correctly. Near type name, line 1, column 119.
Source=System.Data.Entity
Column=119
ErrorContext=type name, line 1, column 119
ErrorDescription=Type 'MvcApplication3.DAL.Product' could not be found. Make sure that the required schemas are loaded and that the namespaces are imported correctly.
Line=1
...
My question is, how can I show it where the Product class is? Its in the project and I've got the using statement at the top. Why can't it find it?
Edit:
Based on the response below, I changed my code to:
var entry = ex.Entries.Single();
var currentValues = entry.CurrentValues.Clone();
entry.Reload();
entry.CurrentValues.SetValues(currentValues);
var clientValues = (Product)entry.Entity;
var databaseValues = (Product)entry.OriginalValues.ToObject();
And that seemed to fix it. But I think it will have issues if the row is deleted. My current problem won't have that issue, so this is a good fix for me. Thanks!

Answer 1

This is a known issue when the context is in a different projects. No workarounds currently exist except for moving the context into the same project.
http://social.msdn.microsoft.com/Forums/en-HK/adodotnetentityframework/thread/fa67aa0e-3bca-44a5-9e00-af6362a539a7
EDIT
Actually I take that back - there is a workaround now listed there since the last time I read this. cool : )