New post in the Announcements Forum:
On October 10th, Steam advised all game developers that we would need to setup 2FA to continue to access the site and update our games.
We made the required changes before the cutoff, (but now Steam has backed off the mandatory implementation of the new authentication.)
Bottom line is implementing the changes they asked for broke the API authentication (it wiped out our API key).
I am currently working to resolve the issues with sending the patch to Steam. I will post an update here when…
R119 Published, Steam clients cannot patch (yet)