It's actually not that simple, Collin. You have to make sure you've entered them in the right order, as there's three keys and they're labeled by number, not by game. Furthermore, by changing the codes this way, the premium modules won't work until you've run the re-installer, which is available from GoG. But only if you've purchased the game from them. So editing nwncdkey.ini really isn't as simple as just changing a few lines, and like I said, I don't feel comfortable posting a walkthrough of that here and having to deal with the people who messed stuff up.
I didn't know that, Calan. Sounds like a more efficient fix than reinstalling. I wonder why GoG didn't just direct us to do that, instead of all that copy-paste reinstaller stuff?