Factorio Forums

I am hosting a multiplayer game for the first time. I have set a password on the game and added her Steam profile name to the admins list. Once it is running, she goes to her profile name in the Steam main window, chooses friends, clicks on my profile name (we are set as friends both ways), sees I am in Factorio, and she clicks Join. It tells her that the mods don't match, and gives her an opportunity to Synchronize. She clicks on that, and it wants a username and password. She has tried every combination of her 3 Steam IDs (why are there 3? I just set up this steam account) and steam password or the game password I set, and always gets the error message: "authentication error on the auth server. user name and password do not match". What is it looking for?

My search-fu has failed. Where is the procedure for joining a multiplayer game documented?

Hmmm. It looks like it may have nothing to do with multi-player. She gets the same phenomenon when trying to manually change the mods, as soon as she clicks the Install tab. It wants a user name and password to even show the mods list. This is a fresh install of Steam on a Mac laptop running OS 10.11 El Capitan.

To access the ingame mod portal you need to link your steam account to a factorio.com account and log in with your factorio.com account: https://www.factorio.com/help