@ railrider1972

I think I would probably re-format the USB and start all over. Also,
I'd advise you not to pull the USB while it is being accessed, and
I'd advise you to make a tar.gz backup of KNOPPIX-DATA every once
in a while in the future, while things are still working ok.

I think I've read that pulling a USB when it's in a read or write process
can cause some real problems with the data on the USB.

If your back-up was made after the problem arose, I expect it may not be
any help in getting things going. It may be bad for a number of reasons.

Sorry to be so pessimistic. Maybe Klaus2008 can give you better news.