false message "Your iCloud storage is full"
iMac OS X 10.11.6
Starting several days ago, applications linked to my iCloud (Notes, Safari, etc) say "Your iCloud storage is full". But System Prefs->iCloud confirms that I use less than 1 GB of my 5GB iCloud allowance.
My problem is similar to the below. Is there now a fix I can do on my own or must I telephone Apple?
(MacWorld, MAC 911, MAY 15, 2017 5:00 What to do when iCloud Storage is obviously empty but Apple says it isn’t)
iMac, OS X El Capitan (10.11.6)