Kobe authorisation

In Adobe Digital Editions on my computer, it indicates that my device is authorised for my e-mail account. I do have an account under this e-mail with ADE. However, when I try to open the book on my Kobo reader, I get a message stating "This document is protected by Adobe Digital Rights Management (DRM) and is not currently authorised for use with your Adobe ID. Please sign in with the authorised Adobe ID and try again."

What am I supposed to do?