Cellular Update Failed
If you see this alert, it might mean there's an issue on the cellular modem of your iPhone or iPad. Your iPhone can't make or receive calls or text messages, or access cellular data.
Apple Pay requires an update
If you see "Your iPad cannot use Apple Pay until it has been updated," you won't be able to use Apple Pay or Wallet for payments or access until you update the iOS on your device. Some Wallet passes might still be available while payments are unavailable.
What to do next
If you restore or erase your iPhone or iPad, you might not be able to activate your device.
If you see either of these alerts, take your iPhone or iPad to an Apple Authorized Service Provider or make a Genius Bar reservation at an Apple Store. You can also contact Apple Support.