Source no longer displayed; what happened? How to fix?

I’ve been using NSight for years and never seen this before.

Suddenly, NSight on VS2013 will not display the source code, except in the Disassembly window.

Yes, the compiler is still set to generate debug information (-G) & -lineinfo. I have not changed the project settings, except to re-enable debug after compiling with it disabled for a while.

Using SDK 6.5. I just upgraded from NSight 4.6 to 4.7 and installed the latest driver 355.82 to try to fix this problem, but no joy.

Is there a particular file needed in the DLL folder for NSight to find the source?

Apparently something went wrong with the driver installation and the new driver was only partially installed. Doing a clean install fixed the NSight problem.

Strange because I had the source code not displayed problem before I even started upgrading the software.