I created a C# solution with two projects.
One project as a front end and the other as a class dll.
The class dll will act as a utility class and created a namespace for it.

The front end project will use this class.
The first time used and compiled works fine.

After some changes are done in the dll class and recompiled this error pops up
A first chance exception of type 'System.IO.FileNotFoundException' occurred in mscorlib.dll

Additional information: File or assembly name c:\dotnet\utilities.dll, or one of its dependencies, was not found.

Any ideas why?

Thanks