I was able to resolve it. I apparently had one registered on factorio.com and had to reset the password to it as the screen name was one of my other ones.

I have been unable to view the multiplayer games for around 3 months now. I keep my version up to date with the latest beta, but I have been occasionally attempting to start playing multiplayer games again. The error I get is that my username/password is incorrect. I have tried both my steam login ...