Microsoft apparently didn't resign all the tools in the SDK supplied with Beta 2 of Visual Studio 2008.  This is actually documented in the readme that UISpy has this issue, which of course, I didn't read..

 

SVCUtil.exe also has this problem and it causes any proxy-generation from VS.NET 2008 to fail (as well as killing the client tester process which is spawned for WCF testing).  You'll know you've hit this error when the program crashes with a "System.IO.FileException" and indicates that it has failed strong-name validation.

 

It's easy enough to fix ..

 

1) Open a command prompt with full admin rights

2) CD to the C:\Program Files\Microsoft SDKs\Windows\V6.0a\bin directory

3) execute "SN -Vr svcutil.exe"

 

This turns off strong-name validation for svcutil.exe.