What causes Visual Studio 2008 SP1 to crash when switch to Design View of a WPF application

The problem was caused by a Visual Studio add-in named, "Power Commands for Visual Studio 2008".

After uninstalling them and restarting Visual Studio, the design view for xaml files began working normally.

Same issue, but without Power Commands installed.The only workaround I've been able to consistently use is to Clean/Rebuild the solution before opening ANY xaml file. If you can't get into your solution because the XAML is loading on start up, delete the suo.

If you wish to keep Power Commands for Visual Studio 2008 installed, see this workaround here:

PowerCommands crashing VS2008 SP1

But basically:

a work around which is a simple modification to the devenv.exe.config file.

This will exist in (64 bit systems) C:\Program Files (x86)\Microsoft Visual Studio 9.0\Common7\IDE

Or (32 bit systems) C:\Program Files\Microsoft Visual Studio 9.0\Common7\IDE

Add this XML token to the dependentAssembly list. They had me add it after the office one, but im not sure if that matters.

<dependentAssembly>  <assemblyIdentity name="office" publicKeyToken="71e9bce111e9429c" culture="neutral"/>  <codeBase version="12.0.0.0" href="PrivateAssemblies\Office12\Office.dll"/></dependentAssembly><!-NEW STUFF--><dependentAssembly>  <assemblyIdentity name="Microsoft.PowerCommands" publicKeyToken="null" culture="neutral"/>  <!-- For 64-bit systems, uncomment this one  <codeBase version="1.1.0.0" href="C:\Program Files (x86)\PowerCommands\Microsoft.PowerCommands.dll"/> -->  <!-- For 32-bit systems, uncomment this one  <codeBase version="1.1.0.0" href="href="C:\Program Files\PowerCommands\Microsoft.PowerCommands.dll"/> --></dependentAssembly>

This worked nicely for me.