I don't know if this is still the case, but you couldn't login if you had 3rd party cookies disabled. Somewhere in the authentication phase, it would silently f

I don't know if this is still the case, but you couldn't login if you had 3rd party cookies disabled. Somewhere in the authentication phase, it would silently fail. No error message like incorrect username/password. You'd get kicked back to the login screen as if you just got there. It was a hassle trying to find exactly which cookies were necessary.