Apple has stopped signing iOS 18.1.1, preventing iPhone users who have upgraded to iOS 18.2 from downgrading to that version of iOS. Apple released iOS 18.2 a week ago on December 11.

Apple often stops signing an older version of iOS, usually within a week or two after a new version is released. When an update is no longer signed, it can't be installed on an ‌iPhone‌ due to a server-side software verification check.

This policy encourages users to keep their operating systems up to date, ensuring they have the latest security enhancements. Apple also stopped signing iOS 17.7.2 on Wednesday.

The iOS 18.1.1 update provided important security fixes, but no other notable changes. In contrast, the iOS 18.2 update brought several new Apple Intelligence features to compatible iPhones. You can find all the details in our comprehensive guide.

Source: Macrumors