after xfering library book to nook, can't open and message says expired, but it is not expired and is readable in ADE

I checked out book from elibrary and downloaded into ADE 4.5. Can read in ADE or OverRead app. Xfered to Nook and can open from Nook device within ADE. Unplug Nook from computer and try to open book. Get error message that book has been returned and in not on record. But still able to find in ADE and OverRead app. Worked fine until last week or so.