Bad news first; your save file got corrupted and it's wiped, hence why it cannot be loaded. I'm really sorry. I'm working on a back-up save data for your save files, so that this won't happen anymore.
Did you crash during your last save? That's the only thing people have had in common; their PC/game crashed at some point.
If you join the Discord I may be able to assist you further, I'd like to get your save file.