I have successfully been using my Kobo ereader regularly with local library downloaded epub books, until this past week. The books look like they have downloaded into the ereader but when I try to open them I get the message - "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 your Adobe ID. Please sign-in with the authorized Adopbe IS and try again. www.kobo.com/help"
My PC laptop with Windows 10 tells me that my authorization is up to date.