Stop stealth updates. Your last update broke appointments, TELL us when you are going to apply an update, WHAT is in the update, and allow us to ROLL BACK if things get broken. So much time and frustration chasing a problem only to find out you updated things, changed or broke the way they work, and didn't tell anyone.
we definitely need a good way to ROLL BACK the update! Yes, a warning before updates with lots of good info would be great.