So I was playing yesterday but had to go do something, didn't close the game properly just hibernated my Macbook, then force quit later. I quit during the pre battle screen and when loaded the save back up got this:
Managed to break the save game system
Hm. I tested out your save game with the current build but did not get any issues. Probably because I made an update to the save game recently and that should have fixed it.
I tried it with the build from a few days ago and had that issue with your save game so things look to be fixed.