https://wccftech.com/fix-ios-12-software-update-failed-error-how-to/

Apple has released iOS 12 on all compatible iPhone and iPad models. The update brings a boatload of new additions and we wouldn’t be surprised if you can’t control your excitement. However, if your excitement is being blocked by an iOS 12 Software Update Failed error, then do not be alarmed. You can try some of the fixes we have listed down below in order to get your update going. Let’s dive in to see some more details on it.

Here are a few easy steps which you can perform to fix the iOS 12 Software Update Failed error.