Ebooks Licence Problem

I recently purchased two books in digital format for my thesis project, "The Cambridge Handbook of Psycholinguistics" from ebooks.com and "The Oxford Handbook of Music Psychology" from google play. The problem I'm having is that when I try to open these books on ADE the screen displays the following message: "E_AUTH_BAD_DEVICE_KEY_OR_PKCS12". I already tried the troubleshooting of both sellers trying to fix this and it won't work, to which they told me I should get assistance directly from you.

Thank you.