Some iPhone X owners are reporting that Face ID is not working after updating to iOS 11.2, 9to5mac reported.
According to users, the iPhone X shows an alert that says it is ‘unable to activate Face ID on this iPhone’ after iOS 11.2 update.
In most cases, Face ID will activate successfully after rebooting your phone.
To turn off iPhone X, hold down the side button and either volume button. Then drag the ‘slide to power off’ slider to shut down the phone. Wait for the screen to go black, hold down the side button to boot the phone up again.
If Face ID does not work after a hard restart, contact Apple Support.
The version of iOS 11.2 was released on Saturday. It corrects the error connected with the constant restarting, and added support for wireless charging and Apple Pay Cash money transfers.