Thank you for your message. I am sorry you are having this problem.
There is currently a service problem reported on status.adobe.com:
I am not sure if that is impacting you or not (it is not impacting my generation).
Is this happening every time? If so, please try a different brower to see if it works in the other browser. If still not working, if you are using a windows computer, try resetting the windows firewall back to the defaults. If none of these work, let us know.