I have been working extensively with both WPF and Silverlight over the past many months. Not too long ago, my workstation started having trouble – specifically Visual Studio 2008 was crashing when trying to open XAML files. Not just crashing either; Visual Studio was disappearing in the blink of an eye.

This started happening every now and then, and became more frequent until it was happening multiple times a day.

After working with some Microsoft people to try and trace down the problem (which we never really did – as it is hard to attach a debugger or other diagnostic tool to VS after it disappears), they suggested I try this patch:

https://connect.microsoft.com/VisualStudio/Downloads/DownloadDetails.aspx?DownloadID=16827&wa=wsignin1.0

(the *.msu are for Vista and Server 2008, and *.exe are for XP and Server 2003, and the x86 patch should be used for 64 bit machines too

Update: For x64 users, you should install the x64 patch, and this will update the 32 bit CLR as part of the installation)

This patch solved my problem. Just like that.

Apparently this patch solves a wider set of problems related to stability when editing or working with XAML files in Visual Studio, and is a generally good thing to apply for developers working with WPF and Silverlight.