Unable to open an ebook on Kobo reader

I am unable to open a ebook I just downloaded from the Library.  It says, This document is protected by Adobe Digital Rights Management (DRM) and is not currently authorize for use with your Adobe ID. Please sign-in with the authorize Adobe ID and try again. www. kobo.com/help.    I checked my PC and I am still authorized.   Where do I go from here?  I have unauthorized and reauthorize and it still did not open.