User Not Activated Error Message on the Nook:
By Andrea in North Conway
Problem: You can't open/read your book because your Nook tells you the "user is not activated."
* Plug the Nook into the computer and simply delete the Adobe Digital Editions folder. I deleted the two that were on my Nook.
* Unplug the Nook.
* Open ADE on your computer.
* Plug your Nook back in. Window pops up and asks you to authenticate your Nook.
* Click yes (or whatever the prompt is) and you are all set.
Yes, the Nook was originally activated/authenticated before, but it simply stopped working for no obvious reason. The solution is to delete all ADE content on the Nook and to re-authenticate/re-activate it.
Here is the link to the forum that helped the most: http://forums.adobe.com/thread/626420
Mac users: One of our patrons recommended these instructions. It includes instructions on deleting a hidden file on your Mac.