Signing in could fail with “redirected you too many times”

If signing in failed for any reason, your browser was sent back to try again straight away — and because the cause was still there, it failed again, until the browser gave up with a “redirected you too many times” error. The reason was never shown, which made a small problem look like the whole service being down. A failed sign-in now lands on a page that explains what happened and waits for you, with a link to try again. The specific fault behind it is fixed too: if you had signed in with Google and later set a password, the two were treated as different people and the password was refused. They are now recognised as the same account, and no existing sign-in method has changed.