WPF

C:\My Source 2010\PHDWebsite\PHDWebsite\obj\Debug\MainPage.g.i.cs(62,42): error CS0234: The type or namespace name 'DockPanel' does not exist in the namespace 'System.Windows.Controls' (are you missing an assembly reference?)

xmlns:controlsToolkit="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Toolkit"

C:\Windows\Microsoft.NET\Framework\v4.0.30319\Microsoft.Common.targets(1360,9): warning MSB3245: Could not resolve this reference. Could not locate the assembly "System.Windows.Controls.Toolkit, Version=2.0.5.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35, processorArchitecture=MSIL". Check to make sure the assembly exists on disk. If this reference is required by your code, you may get compilation errors.

public partial class App : Application
    {
 protected override void OnStartup(StartupEventArgs e)
        {
            base.OnStartup(e);
            MainWindow window = new MainWindow();
            var viewModel = new AllConversationsViewModel();
            MainWindow.DataContext = viewModel;
            window.Show();
        }