I brought sorcerer king rivals about a week and a half ago during the sale and I've been enjoying my time with it, but whenever I get a decent number of turns into a campaign I run into a game ending issue. When I save game during a campaign and then try to load that save it'll say "Unable to load save game because it is not compatible with the current version". This is despite having made the save less than an hour before and there having been no updates to sorcerer king in the meantime. It doesn't happen every time I save, just sometimes, but often enough both the recent manual save and both auto saves are unloadable so I just abandon the campaign.
Here's my most recent auto-save from my latest abandoned campaign: