I cannot open my ebooks on my kobos

My computers and both my Kobos have the Adobe Digital Editions authorization, but, when I disconnect my Kobos from the computer, I can't open the ebooks because of : "Oops! This document couldn't be opened     This document is protected by Adobe Digital Rights Management (DRM) and is not currently authorized for use with you Adobe ID. Please sign-in with the authorized Adobe ID and try again." I did a factory reset on one of the Kobos, reset my computers and my Kobos authorization, but it still tells me that "Oops! This document couldn't be opened". I tried the E_ADEPT_REQUEST_EXPIRED solution, but that has not worked either. What do I do?