Authorize first your computer. Then, insert the USB cable from your nook device to your MAC. Once the device is recognized by your Mac, open Adobe Digital Editions. Once detected Adobe Digital Editions will prompt you to Authorize your nook to the program. Click Authorize then Finish. After the authorization process, the nook device appears as an icon in your library. You can transfer items to and from the device's just by dragging and dropping. Then the books should be in My Documents folder on My Library, or in My Files in My Library. If you are still having troubles with transferring books, call 800-THE BOOK (1800-843-2665)

Had the same problem with mine. What worked for me ...

There was a directory named ".adobe-digital-editions" in the base directory of my Nook. That directory contained what must have been a bogus or corrupt authorization file (.authorize.xml).

Removing that file fixed the problem. After nuking it I ejected the Nook, re-connected it, then when I brought up ADE it asked me to authorize the device.

You won't be able to see a file that begins with a "." in a finder window in OS X. There are ways to configure it to do that, but it's probably easier to just go nuke the directory itself from the command line.

1) Open a terminal window

2) Find the base directory of the Nook: df [enter] (lists all drives on the Mac)

(I don't remember the mount point for things like the Nook, but it will be something like /home/nook or /drive/nook. For this, let's call it /home/nook)

3) Change to the nooks base directory: cd /home/nook [enter]

4) Find that 'hidden' file: ls -la

5a) Move that directory to the side: mv .adobe-digital-editions adobe-digital-broke

or

5b) Nuke that directory rm -rf .adobe-digital-editions

Now, if you eject the nook, plug it back in, then bring up ADE it *should* ask you to authorize it.

Fingers crossed.

/r

Hmmm - double tap. Sry.

Uhmm. YES!! You have to plug your nook device on your PC using the USB cable first, then delete the .adobe folder and/or .digital folder first. Then eject the nook drive. Authorize your computer on Adobe Reader. Then, insert the USB cable from your nook device to your MAC. Once the device is recognized by your Mac, open Adobe Digital Editions. Once detected Adobe Digital Editions will prompt you to Authorize your nook to the program. Click Authorize then Finish. After the authorization process, the nook device appears as an icon in your library. You can transfer items to and from the device's just by dragging and dropping. Then the books should be in My Documents folder on My Library, or in My Files in My Library. If you are still having troubles with transferring books, call 800-THE BOOK (1800-843-2665)

first authorize the computer, after that you just need to authorize the nook device. advice you is to plug in the nook device on the computer and delete the folders on the nook drive, digital editions and adobe digital editions. after that disconnect the nook to the computer, open the adobe digital editions application on the computer. after that plug in or connect the nook device going to the computer after doing that. the adobe digital edition will ask you to authorize the nook device. confirm it afterwards drag and drop the book going again to the nook using the nook device. if problem still persists call the 1800-thebook.