Password does not meet the password policy requirements

When attempting to reset user passwords or create passwords for new users, I receive "Password does not meet the password policy requirements" message.

I am using Windows Server 2016 server as a domain administrator.

I disabled the password complexity requirements (I also tried Not Defined) on the Default Domain Policy GPO. Ran gpupdate /force.

check that any policy applied to your active directory domain controller by gpresult -h c:\result.html command. if your disabling gpo not applied, first open local security policy on your server and disable password complexity then gpupdate /force. then check if you can change password now or not.