Was working fine yesterday. Not it's not.

The only reason I know of that a Google Authenticator code will not work, is that the system time of your mobile device is set wrongly.

I am guessing this is not the case anyway. I will just disable it for you. If you really feel that you need it you could try setting it up again. But I cannot 'fix' Google Authenticator so I cannot make sure it will work for you.