Corrupted save - is it fixable?

Hello! I started a save with someone to teach her how to play, she was about to have her first war when we stopped the session, and now the save is corrupted... We're having another session soon and I'd love to fix this save game instead of having her start over, which could very possibly put her off stellaris forever.

I'm very willing to toy with save edition or anything 😅 I think this may be caused by an event that fired during the game.