[ckruhs]

Same problem here!
There was no problem with the Designer before Anniversary Update.
Now I have to unplug the Dock to get the UWP XAML Designer to work.

Configuration:
- Win10 Anniversary Update (1607 OS Build 14393.0)
- VS2015 Update 3
- DELL XPS15 with Dock Dell D3100


Exception:

COMException: Error HRESULT E_FAIL has been returned from a call to a COM component.
StackTrace:
at Windows.UI.Xaml.DependencyObject.SetValue(Dependen cyProperty dp, Object value)
at Microsoft.VisualStudio.DesignTools.WindowsXamlDesi gner.InstanceBuilders.InlineInstanceBuilder.OnInit ialized(IInstanceBuilderContext context, ViewNode target, Object instance)
at Microsoft.VisualStudio.DesignTools.Platform.Instan ceBuilders.ClrObjectInstanceBuilder.Initialize(IIn stanceBuilderContext context, ViewNode viewNode, Boolean isNewInstance)
at Microsoft.VisualStudio.DesignTools.Platform.Instan ceBuilders.ViewNodeManager.InitializeInstance(IIns tanceBuilder builder, ViewNode viewNode, Boolean isNewInstance)