opening B&N books in ADE

   Hi there.  I installed Nook for Mac, downloaded a book, and moved it from My Documents to ADE. As per instructions from someone on the nook forum. I actually use a Kobo reader, which is why I wanted to move it to ADE. When I tried to move or open the book in version ADE, I got a message saying I needed a user name and unlock code. Back I went to the Nook forum to find out what that is. The same kind person explained, but advised me to upgrade to version 4.whatever first. So I did. Now when I try to open or move that B&N epub book, I get an "ADE closed unexpectedly" error.

???

Thoughts. An epub is an epub, right? I should be able to open it.