I can no longer open library books on my kobo due to adobe id error - can you help please?

I've been downloading library books from overdrive and using digital editions to transfer them to my Kobo glo with no problems at all until now - I now get the following error:

"Oops! This document couldn't be opened.

This document is protected by Adobe Digital

Rights Management (DRM) and is not

currently authorized for us with your adobe

ID. Please sign-in with the authorized Adobe

ID and try again."

I have tried everything that I've seen on these forums and other website including - returning the book and trying another, erasing authorisation and resetting, restoring my kobo to factory settings and starting again and I'm still getting the same message.  Any other suggestions on what to do please?