Apple's latest version of iOS has offered up some interesting enhancements but it has brought with some issues as well. The firm recently released iOS 11.2 in order to fix a number of problems and also address a date-related bug that would cause SpringBoard to crash continuously due to third-party apps using local notifications. Updates usually bring their own problems and it looks like the latest version of the OS has brought a very peculiar one to the iPhone X.
If you have updated to iOS 11.2, you might have noticed that Face ID isn't working on properly on the first reboot. By diving into the settings and trying to reset Face ID, you'll be greeted with the message above in the image, stating that "Face ID is Not Available". The issue seems to affect people randomly, with our iPhone X being affected and only a handful of reports across the internet on various sites and Twitter.
For the time being, it doesn't seem to be a widespread problem. But, if you're an iPhone X owner that has updated to iOS 11.2, feel free comment down below with your experience.
Update: One potential cause of Face ID becoming unavailable on the iPhone X, as noted by Rene Ritchie, may be due to users pre-emptively changing the date on the handset to avoid the SpringBoard crash prior to updating the device to iOS 11.2. All that should be required is to set the date and time to set itself automatically under Settings > General > Date & Time then rebooting the phone to get Face ID working once again.