Commented Unassigned: "The specified view type must derive from ViewBase" still getting the error with 2.4 [21751]

http://imgur.com/Yz9TAnX

I updated all Xceed DLLs via nuget, they all are version 2.4.0.0. The .csproj file also correctly references 2.4 all the way. I restarted the PC and rebuilt the project after upgrading. The UI project is the only project in the solution to reference the Toolkit.
Comments: ** Comment from web user: BoucherS **

Hi,

Using v2.2, I have the same error as you.
Using v2.3 or v2.4, the error is gone.

I'm in VS2012 with Xceed.Wpf.Toolkit.dll and Xceed.Wpf.DataGrid.dll v2.3 (or v2.4).
Here's my code :
```
<Window x:Class="WpfApplication15.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:xctk="http://schemas.xceed.com/wpf/xaml/toolkit"
xmlns:xcdg="http://schemas.xceed.com/wpf/xaml/datagrid"
Title="MainWindow">
<Grid>
<xcdg:DataGridControl x:Name="_datagrid"
AutoCreateColumns="False">
<xcdg:DataGridControl.View>
<xcdg:TableflowView />
</xcdg:DataGridControl.View>

<xcdg:DataGridControl.Columns>
<xcdg:Column FieldName="FirstName"
Title="Name" />
</xcdg:DataGridControl.Columns>
</xcdg:DataGridControl>
</Grid>
</Window>

namespace WpfApplication15
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();

_datagrid.ItemsSource = new List<Person>()
{
new Person() { FirstName = "Bob", LastName = "Smith"},
new Person() { FirstName = "Kim", LastName = "Jones"},
new Person() { FirstName = "Tom", LastName = "Carter"},
new Person() { FirstName = "Mike", LastName = "Santo"},
new Person() { FirstName = "Kelly", LastName = "Sutter"},
};
}
}

public class Person
{
public string FirstName
{
get;
set;
}
public string LastName
{
get;
set;
}
}
}
```