Can you find an intact .DATA folder? – If so, copy it to a new place, create an empty (text only) file with the “same library name”.enl and put that in the same folder as the .DATA folder is located, and try to open that new .enl file. If it works and you sync - you will need to move (I would still save somewhere) the other .DATA folder and .enl file to a backup location and copy both the woirking .DATA folder and newly created .enl folder back to its original location.