I have the same problem - and posted a question... but my question isn't even showing up. I get the same error message. I tried uninstalling ADE and even redownloaded a new installer - but it still doesn't work.
Ultimately I want to associate my Nook - but it seems I need to solve this problem first.
Sometimes ADE gets its registration/activation confused and in a semi-authorized state.
Uninstalling and reinstalling does not help, and indeed installation can even trigger this state.
Unfortunately, it often then gives misleading error messages about what is wrong.
A common incorrect message informs you that the ID is already in use on another computer and cannot be reused.
Another is "E_AUTH_NOT_READY"
This can often be resolved by completely removing any authorization using ctrl-shift-D to the Library screen on ADE (cmd-shift-D if on Mac).
Restart ADE, and then reauthorize with your (old) Adobe ID.
In extreme cases on the mac, the following extra step has helped some people. Navigate to /Users//Library/Application Support/Adobe/Digital Editions and drag the activation.dat file to the trash. If you are using 10.7, see Access hidden user library files | Mac OS 10.7 Lion. http://forums.adobe.com/thread/1265248?tstart=0
That worked. Thanks!
Now I need to get it to "see" my Nook. I connect it, and nothing happens - and I don't see any menu item to "authorize device".
What kind of Nook?
If a dedicated ereader it should show in ADE when plugged in via USB. If it doesn't
- Check a different USB cable
- Check to see if it appears in file manager (Windows Explorer, Mac FInder) as a mounted drive
If not, the probelm is at a lower level than ADE.
- Consider a factory reset of the Nook (with backup first if you have already got books on the Nook that are not held elsewhere)
If a tablet, it probably won't show in ADE.
Install an Adobe DRM compatible app (I suggest Bluefire, also consider Aldiko or Overdrive) if it does not already have such an app.
Authorize the Nook from within the app (details vary from app to app).
Copy books using a file manager to the mounted drive.
It's a Nook HD+. I read in another post (before I saw your answer) that ADE isn't supported on the HD+. I did install Overdrive and that worked just fine.
Thank you for your help!