While trying to compile a demo Silverlight application, I ran into this build error:
System.NotSupportedException: An attempt was made to load an assembly from a network location which would have caused the assembly to be sandboxed in previous versions of the .NET Framework. This release of the .NET Framework does not enable CAS policy by default, so this load may be dangerous. If this load is not intended to sandbox the assembly, please enable the loadFromRemoteSources switch. See http://go.microsoft.com/fwlink/?LinkId=155569 for more information.
The link above provided by Visual Studio is only marginally helpful. Luckily there is stack overflow which had this question/answer: http://stackoverflow.com/questions/1823339/error-building-visual-studio-2010-silverlight-4-projects-on-windows-7-with-xp-mod
The location of my devenv.exe.config is C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE
Sometimes I think Microsoft went overboard with safe computing.