Do you want suggestions?
If so -- try from a different computer.
Try logging off Dropbox and logging back on.
Try de-authorizing Fargo, backup its folder, delete it and and re-authorize it. (copying back the minimum number of files to get your world back)
Basically you want to try starting over without starting over. ;-)
You've gotten away without knowing much about how the software works until now, but at some point shit happens and then you have to dig in.
This is my best advice, not having any idea what the problem is, but having lots of experience digging out of holes.