Apple has stopped signing iOS 9.3 for newer
iOS devices like iPhone 6S, iPad Air 2 which means that users can no
longer downgrade their iOS to that version using iTunes but it is
still being signed for older devices (ie. iPhone 5s).
Apple has stopped signing iOS 9.3 for newer iOS devices like iPhone 6S, iPad Air 2 which means that users can no longer downgrade their iOS
Now you
can’t downgrade to iOS 9.3, If you are on iOS 9.3.1 and also
cannot upgrade to iOS 9.3, if you are on lower versions. So basically
you are forced to upgrade to iOS 9.3.1 directly.
Apple always gives two versions of iOS
to restore whenever it releases a new version. So that people have ability
to downgrade to the previous version if they are not satisfied with
the new one. But after some time, it stops signing the previous version.
You can also visit this link https://ipsw.me to
check the signing status of Apple firmware.
Note: If you are on lower versions like 9.1.2,
9.2, 9.2.1, 9.3 do not upgrade to iOS 9.3.1 because no one knows for
what version of iOS there will be a jailbreak. We all are waiting for jailbreak to
be released. So it’s better to stay on older version of iOS for now.