Did some googling on this and came up dry so I am seeking your assistance.

I am attempting to use FOMM with NV (from GOG). When I go to launch New Vegas I get the following error:

Failed to launch 'falloutNV.exe'
Unable to determine Steam App Id for Fallout: New Vegas

I'm not using Steam since I bought this from GOG. This is befuddling. Any suggestions?

TIA.

Are you using the latest version of FOMM? I know that error has popped up on older versions.

Yes, I just downloaded it from nexus. Unless there is a more recent version elsewhere.

Well son of a gun. Actually, I did not have the latest. I thought I did, but just checked and somehow there is a more recent version than the one I just downloaded. It fixed the problem.

Thank you kind stranger. I am going to take my stupid questions elsewhere now...

There's never any stupid questions, especially in regards to getting Bethesda games running with the least amount of issues. There's always someone around that will help you enjoy the Fallout franchise.

Have fun in the Mojave!