Which ADE version?
Have you tried a different version?
It's the latest version I would assume...I had to download it to download the textbook and I just downloaded it today.
its version 18.104.22.168045
I'm also experiencing the same problem when I try to open books in ADE downloaded from my library (OverDrive). When I try to go to activate.adobe.com I get the following:
"We're sorry, you are not allowed access to the service you requested. If you feel you should have access, please contact the appropriate authorities and give them your IP address: XXX.X.XXX.XXX"
When I download the books on a different network (different router IP) it works, but my home network gets the error above.