Following the launch of iOS 16.5 on May 18, Apple has stopped signing iOS 16.4.1, the previously available version of iOS. Now that iOS 16.4.1 is no longer being signed, iPhone users are prevented from downgrading to that software version.

Apple routinely stops signing older versions of iOS after new releases come out to encourage customers to keep their operating systems up to date, so the fact that iOS 16.4 is no longer being signed is not unusual.

Released on April 7, iOS 16.4.1 was a minor bug fix update that came just under two weeks after the launch of iOS 16.4, an update that introduced new Emoji, Safari Web Push notifications, Voice Isolation for phone calls, and more.

iOS 16.5, the current publicly available version of iOS, brought some important bug fixes and a couple of feature additions, including a dedicated Sports tab in Apple News and a Pride Collection wallpaper for Lock Screens. Apple is also testing iOS 16.6 with developers and public beta testers.

Source: Macrumors