It say: HTTP 500 (Internal Server Error).
It happens with any of the three browsers I've used, and I've also disable an anti-virus. I've checked on another computer at home (same home network) and it didn't work as well (the same error). That's pretty weird as it just suddenly stopped working.
PS. However it's working on MacBook Air. It means it refuses to work on Windows 7 (Chrome, IE and Firefox).