I am having the same problem, but have no solutions
I have a Kobo reader with the same problem. I can download books from the public library, and just bought two books from Kobo. I can read them on my computer, but can't open them on my reader; I get the same "OOPS" message. I've authorized my computer and the reader and under "Authorization Information", both devices have the same Adobe User ID number. The eReader is new but there's something about it that Adobe doesn't like.
I've had these tussles with Adobe, and there's something about Adobe that I don't like.
Addendum: My Kobo reader gave up the ghost completely. Still under warranty, I received a replacement unit and, guess what--this problem with opening downloaded books is gone! I can read books that I've recently purchased, plus a library book that I downloaded an hour ago.
Beats me why--if another problem surfaces I'll tap an add-on to this add-on.
I have a similar problem. I had a problem with my Kobo Glo and it was replaced under warranty. About the same time follow a recommendation to update to the newest release of ADE. Since then I have been unable to transfer books to the reader from the PC. I know the licenses are good, but books transferred to the reader won't open. Very frustrating, and Adobe doesn't appear to have any interest in providing actual support. Sad.
I really sympathize with you, your problem is all too familiar to me!
The only thing that I can tell you is that the Kobo reader I bought
originally, stopped working completely; I sent it back for warranty repair /
replacement, and the new unit they sent back has worked perfectly. My
original Kobo reader would not open downloaded library books; the new unit
does without any difficulty.
I am using a Kobo Aura HD. I think that their quality control must not be
very good, but how can we be sure? I know Adobe won't let me open any books
I had on my old Sony reader. To me, Adobe is stifling our right to buy and
read any books we want to.
The user forum in Adobe has complaint after complaint from people who are
locked out of the books they have bought, due to Digital Rights Management.
This must be hurting the purchase of new books; why buy a book and take the
chance that you won't be able to open and read it, when you can download
books to borrow from the library that don't cost anything.
If I were you I would contact Kobo about getting your reader repaired or
replaced. The fact that mine worked after Kobo sent me a new unit, tells me
that the problem was with the reader. However, Adobe makes me very angry.
I wish we could start a class-action suit against Adobe.
Good luck with getting your problem solved. Please tell me how you are
doing with this!