The login AU error message prompts this because Apple has updated the protocol and needs to log in to the APPID Management Center to agree to the privacy agreement. After agreeing, you can log in to the AU.

 

 

Open login https://appleid.apple.com,It will pop up automatically, and then click to continue (if there is no pop-up to log out again or log in to another browser), you can log in and use it when you return to AU.