Try a different computer, if it works you've isolated the problem to your own device, if it doesn't work you'll need to Send Feedback, quoting devices and operating systems (eg iPad iOS7 or Windows7 Firefox) to get the problem fixed.
If it's on your computer, try an alternate page such as chessatwork.com or timeforchess.com. If that doesn't work, come back and we'll go further in.
