The update was meant to fix the iPhone X's Springboard problem, but broke Face ID instead.
Apple has rushed out an update to address a crashing issue on the iPhone X, but inadvertently caused Face ID to break instead, according to 9to5Mac.
The iOS 11.2 update to the iPhone X was issued after users reported their handsets crashed at 12.15am on Saturday morning, thanks to a flaw affecting Springboard, the application that manages the iOS homescreen.
But after installing the update, some users said they were presented with the messages "Face ID is not available" or "Unable to activate Face ID on this iPhone."
It would seem the issue isn't as problematic as the Springboard flaw though, with users able to simply restart their device to get Face ID up and running again.
The iOS 11.2 update wasn't due to come out just yet, but Apple was so concerned by the Springboard fault, it rushed through the new version - potentially neglecting to test it properly. However, Apple analyst Rene Ritchie seems to think the problem was caused by users changing the time on the clock before installing the update in the hope it would revive their crashed iPhone.
"If you changed your #iPhoneX date to avoid the springboard crash, then updated to iOS 11.2, #FaceID won’t like the bad date and you’ll need to reboot to make it happy again. (Also: remember to set your date/time back to auto ASAP.)," he said on Twitter.