Fun time with iOS error “Turn on two-factor authentication to use Messages”. We are very surprised and highly disappointed at Apple remotely turning off Messages without warning on my iPhone today. The way I found out was my wife wondering why I didn’t return her messages. Turned out that sometime today Apple turned off iCloud Messages. Any attempt to turn it back on results in “Turn on two-factor authentication to use Messages.” I don’t remember seeing any announcement for the 2FA requirement. Can someone point out if there is an announcement? I never used Messages in iCloud by the way, and didn't change phone or iOS version in the past week. Different iPhone with different iOS versions are impacted. From iPhone XS to iPhone 6S, iOS 12.0.1 and 11.4.1.