I later noticed I had a cascade of 4 of these error windows.

I didn't know what caused it, so I just closed them.
The next day when the computer was booted up, the error message came right up.
I did a system restore, which fixed it, and also restored the previous version of FBackup.
I just got around to reinstalling 5.0.300, and the message came up right after the installation.
I rebooted, and the message came right up again.
I uninstalled FBackup, rebooted, and that fixed it. So now I'm sure that FBackup is the cause of the problem.
My problem now is, how do I get the previous version back? I think that if I run the previous setup.exc, it will just download the broken version again.
I think I'm screwed!

(Running WIndows 8.1 if that matters).