I was having the same problem too. You should try removing the ereader from your devices on your computer. then re-connect it and synchronize it. It may help.
I think this is a duplicate posting from yesterday.
thanks frost32.. tried but no luck sad to say
I answered this post the first time. Please see that answer.
Frustrated, I am sure we would like to see your reply but i couldn't find the other post which you are talking about. Can you please give its link. Thank you.
I'm sorry, but I get really 'frustrated' with people who double-post
because they want an answer faster - or something.
I do not have the link you want me to post, so let me put it another way.
There's a sequence to follow to attach your ereader, then transfer ebooks
to it and then close. You MUST let the ereader finish processing files
before you pull its plug, and I think that's the issue here. Delete the
ebooks that won't open on the Nook. Then, reattach and retransfer them to
the Nook. When you're done, close ADE, but do not pull the plug on the
Nook until its screen says it's done processing new content.
OMGosh i did not know i double posted!! really sorry about that..... thank
you so much for your help.. im a real newbie to this type of thing
(probably why i ended up double posting..lol)....ill give it another try...
im sure once i get the knack of it ill be away enjoying my books again..
Thanks Fustrated. I though that was quite obvious, so i didn't state that. But i am also guessing now that that was the reason ame was having the problem.