Cellular update failed after iOS update. I can’t update to iOS 12.1.3 either. I have WiFi connection still it says update failed. Any possible solutions?

Follow These Quick Tips To Troubleshoot iOS 12 Installation Problems

* Update iTunes first, if using iTunes to update your device(s)

* Check your network connections (WiFi and Ethernet, if applicable)

* Toggle WiFi Off and On to force a refresh to your network

* Check Apple’s System Status report for any server outages or issues

* If you have difficulty updating iOS over the air using Settings > General >Software Update, try iTunes

* Force restart your iDevice(s)

* Delete then re-download the iOS Update file

* If you see an insufficient space warning, free up some space on your iPhone or other iDevices

* A few readers suggest opening up a bit more space than the update itself—things seem to go a lot more smoothly with that extra cushion

iPhone, iPod, and iPad Device Setup and Compatibility 

* The most obvious iOS Install error is around device compatibility. Your device needs to be compatible or eligible for iOS 12 update

* The second install error is related to your device parameters. A typical iOS update requires at least 5GB – 7GB free storage. If you do not have adequate storage, you get errors during the installation process.

* The third element is around the device update setup process. If you have chosen to automatically update to latest iOS when available, Apple requires that your iPhone or iPad is on the charger and you are connected to WiFi before it can apply automatic updates.

Network Bandwidth and iOS 12 Downloading Issues

* The next issue that users face is around network bandwidth while trying to download the install from Apple Servers.

* Make sure that you are connected to a strong WiFi and stable network. 

• * If concerned about your WiFi strength and stability, try iTunes instead