Ok ! So there are two parts to the issue !
1) Click on the help menu and then choose "AUTHORIZATION INFORMATION". In the pop up window if you are able to see that Adobe Digital Edition is authorized to your Adobe ID (Your Email Address), then the first part is GOOD.
Just incase after choosing "AUTHORIZATION INFORMATION" you see that Adobe Digital Editions is authorized "WITHOUT" an Adobe ID then:
a) Get to the library view.
b) Press Ctrl + Shift + D
c) In the popup window choose "ERASE DEVICE AUTHORIZATION".
d) Now go up to the help menu again and then choose "AUTHORIZE COMPUTER".
2) This part is where NOOK gets authorized with Adobe ID and then enables ebook tranfer to NOOK.
a) Once you have Digital Editions running, connect Nook to the computer.
b) Once Nook shows up in the Left hand panel of Digital Editions click on NOOK icon then click the small "GEAR ICON" above it.
c) Choose "AUTHORIZE DEVICE", this will prompt you to authorize NOOK with the Adobe ID you entered in step 1.
Once the device has been successfully authorizes switch over to the Library bookshelf and then click and drag and drop an ebook over the NOOK icon towards the left.
THIS SHOULD WORK.
If not then try redownloading the ebook from the Library that you use (Public library etc) and then copy that over to NOOK.
So I just came across this problem this morning. I do not keep my WiFi turned on as it slows down my internet alot. I have a Nook Simple Touch. I found the solution by:
2.Connecting you Nook to your computer
3.Go to My Computer and find your Nook
4.Click on Nook and delete adobe digital editions from the right hand column
5.Disconnect your Nook---again!
6.Open ADE on your computer and it should ask you to authorize your Nook again...do so.
7.Slide your epub books to your Nook.
This worked for me. Thank goodness or I was going to go into a *rage* lol. I believe it has to do with the Nook update, but I didn't notice it until I turned on my WiFi and Nook did this update last night. Your books will be found in my digital editions now. On my Nook Simple Touch I have my library set to ALL so I see everything at once. Hope this helps you.