PLEASE HELP - Can not access vault files

I have the same problem. Been using a 32GB Extreme for a couple of years but needed the drive to backup my laptop so I copy/pasted everything to desktop while while waiting for my new Sandisk Extreme 64GB to arrive, to my horror, everything I have in the fault is now encrypted even though I migrate them over to the newly arrived drive. Only strange characters showing. I log in as usual, open the vault and tried opening the screwed-up file with pdf reader, word, excel, note, etc…nothing reads, just a whole bunch of characters.