Apple officially locked iOS 11.3 sign

Today Apple has been the key to sign iOS 11.3, after a week of launching iOS 11.3.1. This means that users cannot undo the old operating system version after they have uploaded to iOS 11.3.

Therefore, if you are using a 64-bit iOS device or more like iPhone 5s, you only have one version to restore, which is iOS 11.3.1 (next to iOS 11.4 beta).

When there is a new release, Apple will often block the sign of the old iOS versions to ensure that more users will upgrade to newer versions.

IOS 11.3 version is released with a lot of improvements, especially added features to increase performance and can turn off the feature to slow down the device when the battery bottle. Although it has a few minor bugs related to security, but soon Apple has released iOS 11.3.1 to fix. And today, Apple officially stopped allowing to return to iOS 11.3.

Currently, Apple is releasing beta 11.4 beta versions for developers and test program participants, most recently iOS 11.4 Developer beta 3, adding many new features. Once stable, the company will launch the official version and continue to lock iOS 11.3.1

See more:

1. Fix battery drain on iPhone when updating to iOS 11.3
2. iOS 11.3 disables iPhone touch screen being replaced by 3rd party
3. Common errors after iOS 11.3 update