Why can't I move library books from ADE to Nook anymore?

I have had my nook for years. Always taking out library books to read on it.  Last few months I keep getting error messages. While the book shows up on the Nook in my library, when I try to open it I get error messages.  Not always the same message, but today it says "Loan token not found". I have unauthorized my nook and reauthorized it, deleted the previous version of ADE and loaded the latest, rebooted everything. 

Any ideas?