I seem to be getting the same thing now. When I try to start a game from battlelog I get an annoying box that says "download and install the latest browser plugin to play the gam". I dl it, execute it, restart firefox, and get the same dialog box. Tried everything I could find online plus the suggestion in this thread, but I can no longer start a game battlelog. I don't much like the new UI but I would use it if I could get battlescreen, but I don't know how to get battlescreen when using the new UI. So anyone else have this issue and solve it?