"E_AUTH_BAD_DEVICE_KEY_OR_PKCS12" error when downloading new Ebook

[books_are_the_best]

The Ebook seller had reset the ebook so I can download the link again and I have received the same message.  Today, October 13th, 2013, I deleted my Adobe Digital Editions App, downloaded it again, reinstalled it without any errors.  I can open up any of my exsisting books in my Adobe Digital Editions Library.  This is on an IMac, V 10.7.5, 4 GB memory, upgraded to larger hard drive several weeks ago.  Any suggestions would very much be appreciated.  I am a visually handicapped adult and can no longer read many paperback books, small fonts in books etc...

[sjpt]

Some ebook sellers use the Adobe DRM mechanism, but rather than relying on the Adobe ID for authorization have their own Vendor ID (their own user/password).

You could be able to read your old books but not the new one if all the old books used the Adobe ID, but the new one used a separate Vendor ID.

Check with the ebook seller if you should be using a separate  Vendor ID.

ADE1.7.2 does not support different vendor IDs.  V2.0 does, but I am not sure exactly how to get it to do so.

The user guide says ' The best way to do this is to supply an Adobe ID or Vendor ID, associating the book with your ID.',

but doesn't say how to do this.