Digital Edition could not connect to the activation server

Several days ago my laptop was reinstalled because some errors. At first when i download again the ADE, i can open the epub files that was protected by DRM. But now, it asks me to authorize the computer before opening it. I've already tried it, and the dialog box said "Could not connect to the activation server. Please make sure you are connected to the Internet". I have already connected to the internet, i've already turned off my firewall, reinstall the ADE, remove the files and open up again the files that i want to open (basically i'm trying everything, because i'm in the middle of working on my thesis). Please, can anybody help me?