found the answer elsewhere on this site.
May I ask what the solution was? I am having the same problem/error message. Thanks.
It's tied to your credit card that you used to purchase the book. User name is name listed on card, number is credit card number. My name on my card includes my middle initial but not on account with Barnes and Noble account. Even if it's a free book, I think you still have to used this process. By the way, have you tried David C. Books? Daily email offerings, free or low cost. Hope this helps.