Persistent message re iCloud after updating MacBook Pro to Mojave OS 10.14.

On my MacBook Pro (Mojave 10:14) a message appears on the iCloud window "Update Apple ID Settings. Some account services will not be available until you sign in again." I've clicked on "Continue" and signed in with user name and password to no avail. The notification at Settings on the dock and on iCloud in the settings window, with the same message, still appears. I've ventured into signing out from iCloud, but the warning about possibly losing all my data seems too alarming to risk.

What does the message require, and how do I get rid of the notification and the message itself?