Others can join my lobby, but I can't join theirs

Age of Empires II: DE II - Report a Bug
1

Game Version:101.101.342230.0 4509956

  • Build (####)
  • Platform Steam

Issue:

I can host a lobby, and invite friends via Steam Invites, and we are able to play. But . . . if any friend creates a lobby and invites me, I can’t join and get an “Unknown Error” message.

Reproduction Steps:

  1. Have a friend create a lobby
  2. Have them invite you into the lobby
  3. Accept the invitation!
    CannotJoinGame
    CannotJoinGame839×498 40.4 KB

    (SCREENSHOT ABOVE)
2

If I log onto a different Steam Account on my computer, I do not have the problem. I used Family sharing to run the game, so all the files are the same. As far as I can tell the settings for both accounts are the same, so this problem appears to be linked to my account, but I don’t know how, and thus I have no idea of how to fix it.