Q: 'New password must not be used in pass year' keep appearing when I tried to change to a new password, what should I do?

"Pass" year or "past" year?

Try a password that you have not used in the past 12 months.

That means the password you are trying to save you have used as your password in the last 12 months. Try a different password.

I have the same problem. I tried a randomly entered string of characters and number several times and get the same error. End result: I can't change my password at all.

Call AppleCare and ask to be transferred to the Account Security Team.