There is no source code available for the current location

If you see this error then you need to tell VS where to look for the source code. Let me explain with an example.

Once one of my developers approached me when using enterprise library 5.0. The command he was trying to debug was
EnterpriseLibraryContainer.Current.GetInstance<ExceptionManager>();
The code for that command lies in the enterprise library source code. The screen shots below show how to solve the problem

Solution property Debug Source Files 

Add the directory containing the source code

Just click OK and try debugging again. It will step into those source code files that you just added.