I tried to go on, but this message came up... "You have third-party cookies disabled in your browser, which is likely to cause problems. You should enable them and then refresh this page." ??? There also seems to be something wrong with the regular Showdown page...
To enable third party cookies in Chrome:
[*.]pokemonshowdown.com
[*.]showdown.pokemondb.net
My Mac had the same problems but I never witnessed any problems. It's nothing major and it should correct itself lafter. For now just click 'Ok'.