I’ve had a similar issue happen before from moving individual saves around. Try doing the following:
1. Back up your entire save folder just in case.
2. Move your save folder somewhere else, so there is no “save” folder in the game’s directory.
3. Start a new game, then save the game in all of the slot numbers that correspond to the saves that you’re trying to recover.
4. Close the game, and copy + paste your actual saves in the “save” folder - replacing the new “dummy” saves you made.
5. Run the game, and see if your saves can be loaded normally.
Let me know how it goes! ❤️
Edit: Also, assuming you’re on Windows… I suggest having your game directory stored in a folder somewhere on your drives (instead of somewhere like your Desktop or Downloads folder).