if you get the following error:
The configuration editor was unable to load an assembly A first chance exception of type ‘System.IO.FileLoadException’ occurred in mscorlib.dll File name: ‘Microsoft.Practices.EnterpriseLibrary.Validation, Version=5.0.505.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35’
then its probably because you did not install the “Microsoft Enterprise Library 5.0 Optional Update 1” that you can find it in: here
becuase you are trying to run some assemblies that are trying to use the updated version of EntLib but they can’t find them.
if the installer fails, make sure you have closed all instances of Visual studio, and if it again fails then, restart the windows, then un-install Entlib, then run the installer for update 1.
This error occurred wit me when trying to run the “Enterprise Library Contrib Project”