Apparently the 8th save game slot wasn't functioning properly. If you had previously saved a game here, while you'd still have been able to continue the game via the "Continue Last Game" button, you couldn't have loaded it from its proper slot. This has been fixed. If you want to play 8 campaigns simultaneously, or have a huge family all wanting their own campaigns, all should now be well!
Patch Update Ver. 1.03
Source: Steam Community (opens in a new tab)
Build and release context
Steam update times within 24 hours of this post. Matching dates do not confirm which build it describes.
Build 8784464 · public branch
Steam updated · First observed