- Apr 12, 2001
iPhone, iPad, and iPod touch owners who have upgraded to iOS 12.1.4 will no longer be able to downgrade to iOS 12.1.3.
iOS 12.1.4, available on all devices able to run iOS 12, was a bug fix update that addressed a serious Group FaceTime security vulnerability.
Apple routinely stops signing older versions of software updates after new releases come out in order to encourage customers to keep their operating systems up to date.
iOS 12.1.4 is now the only version of iOS that can be installed on iPhones and iPads, but developers and public beta testers can download iOS 12.2, a major update that's currently being beta tested and is expected to be released next week.
Article Link: Apple Stops Signing iOS 12.1.3 Following Release of iOS 12.1.4