MDT/WSIM fails to catalog a captured Windows 7 image

Had an issue today where I was trying to catalog a captured Windows 7 WIM image, both through MDT 2010 and through WSIM directly.

Doing so comes up with an error:

Performing operation "generate" on Target "Catalog".
The operation failed to complete.
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.ArgumentNullException: String reference not set to an instance of a String.
Parameter name: source
   at System.Globalization.CompareInfo.IsPrefix(String source, String prefix, CompareOptions options)
   at ?A0xfe36268f.ConvertToNtPath(String path)
   at Microsoft.ComponentStudio.ComponentPlatformInterface.CbsSessionAdaptor..ctor(String bootDrive, String imageWinDir, String servicingPath)
   at Microsoft.ComponentStudio.ComponentPlatformInterface.OfflineImageImpl.InitializePackages()
   at Microsoft.ComponentStudio.ComponentPlatformInterface.OfflineImageImpl..ctor(OfflineImageInfo imageInfo)
   --- End of inner exception stack trace ---
   at System.RuntimeMethodHandle._InvokeConstructor(Object[] args, SignatureStruct& signature, IntPtr declaringType)
   at System.Reflection.RuntimeConstructorInfo.Invoke(BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at System.RuntimeType.CreateInstanceImpl(BindingFlags bindingAttr, Binder binder, Object[] args, CultureInfo culture, Object[] activationAttributes)
   at Microsoft.ComponentStudio.ComponentPlatformInterface.Cpi.PlatformImplementation.CreateOfflineImageInstance(OfflineImageInfo imageInfo)

The captured image I was trying to work with was of a 32-bit machine, and the WAIK tools I have installed on my desktop are the 64-bit ones.

The solution, as I learned here after a bit of searching, is to re-run the catalog operation on an x86 machine.

As you can’t install the 32-bit tools on a 64-bit machine, I installed the 32-bit tools on my laptop, fired up WSIM, opened the WIM image, re-ran the catalog operation, and it succeeded without errors.

You’d think that they could catch the exception and give you a useful message about running the catalog again on a compatible machine, but no…