If an alert says Face ID has an issue on your iPhone or iPad Pro
If you see a "Face ID issue detected" alert or a "Face ID has been disabled" message in your parts and service history, your iPhone or iPad might need an update or service.
You might see the following message on your iPhone X or later, iPad Pro 12.9-inch (3rd generation) or later, or iPad Pro 11-inch (1st generation) or later:
"A problem was detected with the TrueDepth Camera. Face ID has been disabled."
What to do next
Update your iPhone or iPad to the latest version of iOS or iPadOS
If you still can't enroll your face or unlock your iPhone or iPad with Face ID, you might need service. Get service
Only a trained technician should service your device. Improper repair, modification, or use of nongenuine components in the laser systems might prevent the safety mechanisms from functioning properly and could cause hazardous exposure and injury to eyes or skin.
What the message means
Using diagnostics available in iOS 14.6 or later, Apple has detected an issue with your TrueDepth camera that might cause it to not function as expected. The TrueDepth camera contains lasers, which might be disabled for safety reasons if the device malfunctions or is damaged. This won't prevent you from using your iPhone or iPad, but until your iPhone or iPad is updated or serviced, you might not be able to use Face ID, Animoji, Memoji, and some other features that use the front camera.