Hello, i have the same problem. Could be the licensing server? I have the problem with a book bought from an online bookstore at Portugal.
I don't know, but I bought the book from an online bookstore in Portugal as well.
I bought it at bertrand.pt.
Probably they have change something on their acsm file, or do not adapt to some change made by ADE. I sent an email to bertrand.pt explaining the situation.
I will keep you updated.
Mine was on a different store (wook.pt). I already send them an email too.
Thanks, I will do the same!
The problem is solved (for me at least).
I tried to download the book again and it worked for me too!
Thanks for the help.