I'm not sure what the issue is at this point but I am looking into it, I've had one other user report this issue but others do use Firefox and my own tests with Firefox come through fine. It may be an extension you're running etc.
The only browsers we block is the stock browser on iPhone / iPad b/c it lags the game and Opera. If you're unable to get in with Firefox you might try Chrome.
Posted by Solstice
on 10.30.2015 (10.30.2015)