There is a thread on this on the EA forum, and while they don't have a solution to it, there is updates which suggests there may be some light at the end of the tunnel:
Originally Posted by EA WEBSITE
Right now, the official message is “Currently, we're looking into the technical issues of the Mask Creator featured on the Army of TWO website.”
I know this does not help but I just want you to know that the dev team is aware of the issue.
The thread is here:
Might be worth everyone commenting so they see there are people interested in this, hopefully they can come up with a solution for us.