Apple has stopped the signature of iOS 11.3.1. This means that downgrading to this outdated version is no longer possible.
Apple stops signature of iOS 11.3.1
It is quite normal for Apple to discontinue the signature of older versions of iOS from time to time. Now it has hit iOS 11.3.1. This means, conversely, that a downgrade to this older iOS version is no longer possible. This is a normal process that occurs at Apple on a regular basis.
In late May, Apple has theApproved. The update includes AirPlay and news on iCloud. Apple granted after the release of a new version of iOS a certain time window, so that a downgrade to an older version grds. is possible. This can sometimes be useful if problems occur with the new version.
iOS 11.4 runs very stable on our devices. Real problems did not really come across our way. Currently the work is already running on iOS 12.has already been released. The final version is expected for autumn.