Yes sorry I restarted the server to store a machine image. Working now!
Tomorrow we're going to have another very short outage when we deploy a new version, with some nice new features. Apologies for any inconvenience.
If you get a
401 Server Error pop up, then make sure that you are logged in if you have a user account. It seems sometimes the auth cookie goes stale, or something (I'm not a web developer!). We're working to fix this, meanwhile on some platforms, some browsers this could be an issue when your session times out.