I hit "my games", then the highlighted game, but no board appears.

You've tried all the usual things - clearing cache, restarting browser, restarting computer - and nothing helped. Are you using a PC, tablet, phone?

I'm having, as of yesterday, precisely the same problem, i.e., no board appearing when 'your move' is clicked. Win-XP with FF

Firefox's recent Java updates have produced some reported problems. If that's the cause, they usually fix within about 48 hours.

Thanks for the update, KP.