impossible add to designer (VS c# WPF)

[Titibo26]

Hey,

When i try to add both UIOpenTKControl or threading one into the designer of my C# apps, it gives me an error :

"ArgumentNullException : Value can't be null. Parameter name : window"

I think it's making some trouble on my XAML code. Tried to fixe it but i didn't find the solution. I tried to reinstal everything. Same error occurs with the example solution. BackTrace is :

à System.Windows.Interop.WindowInteropHelper..ctor(Window window) à OpenTkControl.OpenTkControlBase.OnLoaded(Object sender, RoutedEventArgs args) à OpenTkControl.UiOpenTkControl.OnLoaded(Object sender, RoutedEventArgs args) à OpenTkControl.OpenTkControlBase.<.ctor>b__49_5(Object sender, RoutedEventArgs args) à System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs) à System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised) à System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args) à System.Windows.UIElement.RaiseEvent(RoutedEventArgs e) à System.Windows.BroadcastEventHelper.BroadcastEvent(DependencyObject root, RoutedEvent routedEvent) à System.Windows.BroadcastEventHelper.BroadcastLoadedEvent(Object root) à MS.Internal.LoadedOrUnloadedOperation.DoWork() à System.Windows.Media.MediaContext.FireLoadedPendingCallbacks() à System.Windows.Media.MediaContext.FireInvokeOnRenderCallbacks() à System.Windows.Media.MediaContext.RenderMessageHandlerCore(Object resizedCompositionTarget) à System.Windows.Media.MediaContext.RenderMessageHandler(Object resizedCompositionTarget) à System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs) à System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)

Thank you very much,