Thanks for sharing this error, I’ll check it and fix it for the next version, you’re the first one to report it. I’m very sorry about what happened with your save, did you never save before? where do you have the save files? Ideally you should save from time to time.
Even if you didn’t make a manual save, it’s possible that you still have auto-saves. They are stored under the letter A in the Load menu (that’s the auto-save page at the bottom). You might find a save from just before the problem there. If not, keep that current save file — when I fix the issue in the next version, you may be able to use the Back function to step out of the error.