Please check the following:
1. Open the file in Adobe Digital Editions.
2. Go to File -> Item Info
Check under permissions, Copying permission
Did what you suggested. Now there is: ioerror.
I have the same issue and this comment was not helpful. There's no way to change the copying permission so that I can have the book on my Nook. Please tell me how I can resolve this!
I am having the same issue but mine is a Kobo e-reader. I have tried de-authrozing and re-authorizing. I have sent the books back to the library and down loaded again.