Error message: Oops! Unable to open this document. This document is protected by Adobe's Digital Rights Management (DRM) and cannot be opened with your Adobe ID
This error occurs when you have downloaded an ebook and transferred it to an e-reader that has not been authorized using the same Adobe ID as the one used by the Adobe Digital Editions application.
To solve the problem, you must re-authorize your e-reader. Please refer to the procedure in the e-readers getting started guide.