Choose Help > Sign In (if this is dimmed, you're already signed in and don’t need to activate your software).
Sign in with your Adobe ID and password.
Authorize your computer: choose Help > Authorize Computer.
Make sure that any firewall, antivirus, and proxy software on your computer isn’t blocking ADE servers. You can also check whether http://adeactivate.adobe.com/ is blocked. If it's not blocked, you should see "Welcome to Digital Editions."
If you still have trouble, please contact Adobe for additional support.
Thank you for your patience and understanding. I hope this issue will be resolved very soon. Have a great day!
Scott T The Google Support Team
None of it helped, and so I am reaching out to you. When I try to add the book/epub to ADE I get the error message "Unable to download. Error getting License. License Server Communication Problem: E_GOOGLE_DEVICE_LIMIT_REACHED" or "E_ACT_NOT_READY". Please advice on how to correct this.