The located assembly's manifest definition does not match the assembly reference

Question

I am trying to run some unit tests in a C# Windows Forms application (Visual Studio 2005), and I get the following error:

System.IO.FileLoadException: Co

Answer 1

The other answers wouldn't work for me. If you don't care about the version and you just want your app to run then right click on the reference and set 'specific version' to false...This worked for me.