Visual Studio 2010 WPF Designer issues

I am using: Visual Studio 2010 Professional, Silverlight 4 Toolkit

The WPF Designer don't show (invisible) - while the Component Toolbox is showing the relevant controls, and the Windows->Windows option shows the designer to be active. It does this with ALL XAML for me, regardless of its complexity. I have already tried the /ResetSkipPkgs to no avail. I had CodeRush and DevExpress installed (demo) version but removed both since. I can get along with XAML by switching to Source Code /Text Editor, but this really boils my chops to run the app to find out that I have made a silly mistake in my XAML (while a preview would sort it out quicker, and no, please don't suggest Expression Blend for it is non-nonsensical for me to switch continuously between these applications).

When I however switch the WPF Designer to open with Encoding I get the following error - which I assume is related to the issue for not showing the XAML Editor/Designer in non-encoding:

An Unhandled Exception has occurred

Click to reload the designer

System.NullReferenceException

Object Reference not set to an instance of an object.

at MS.Internal.Providers.VSDesignerContext.VSDesignerContextHolder..ctor(IServiceProvider services, VSDesignerContext context, Object docData) at MS.Internal.Providers.VSDesignerContext.GetContext(IServiceProvider services, IVsWindowFrame frame, Boolean createIfNotExist) at MS.Internal.Designer.TabbedEditorPane.MS.Internal.Designer.ITabbedEditorService.get_DesignerContext() at MS.Internal.Designer.DesignerPane.InitializeDesigner()

I have googled it silly, to no avail. I am thinking about reinstalling Visual Studio开发者_Go百科 - but this REALLY is a last resort. I hate fixing things by reinstalling, rebooting etc.

Any guru with the magical answer?

I got the exact same exception today and solved it by killing a few GDI hungry apps. You can see the number of GDI objects a process is using in the Processes tab of Task manager (you will probably need to add the column using View -> Select Columns).

Hmm, I know this is old, but you should try installing SP1 for your Visual Studio if you haven't yet.