How to resolve: “Important message: Camera Unknown Part” notification

If your iPhone has a history of Camera replacement / Repair / Service from an un-authorised service provider then the only option that you have is to take the device to...

Take your device to an Apple Retail Store or Apple Authorized Service Provider, or contact Apple Support:

Find Locations - Location Selector - Apple

Contact Apple for support and service - Apple Support 

Get a Genius Bar Reservation and Apple Support Options - Apple

Contact Genius Bar.

Manage Reservations - My Reservations - Apple

Parts and service history

With iOS 15.2 and later and iPhone XR, iPhone XS models, and later—including iPhone SE (2nd and 3rd generation)—you can go to Settings > General > About for the parts and service history of your iPhone. You can also find out if the battery has been replaced. If the replacement was done using genuine Apple parts and processes, "Genuine Apple Part" will appear next to Battery.

Do you have a disabled Face ID alert on your device?

Please read the "What to do Next" section in this link, if nothing works as per the instruction given in this link --> If an alert says Face ID has been disabled on your iPhone or iPad Pro

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12 Pro Max here,

same issue immediately after updating to 16.4.1!!!

went to Apple Store and they literally pretended like they never heard of such a thing lol.

they tried to charge me $200 to fix something THEY BROKE!!!!

Apple is a joke anymore and not a funny one….

Really such bs that apple breaks our phones on purpose the day AppleCare expires so now I have to arrange my schedule and go to the store for you to tell me that it’s now broken and I have to pay 100$ for a refurbished phone. Just fix the update or replace my phone.