Today, Apple issued an official support document outlining possible problems users may encounter when setting up the new iPhone 14 and iPhone 14 Pro. iMessage and FaceTime may not activate correctly on iOS 16.0. Some users have reported problems with receiving iMessage or FaceTime calls after updating to iOS 14. In contrast, others have seen green bubbles instead of blue ones while corresponding with other iMessage users.
In a nutshell, iOS 16.0 introduces additional problems to the device setup process connected to activating the device with iMessage and FaceTime. The timing couldn’t be worse, considering that many people are buying iPhone 14, iPhone 14 Pro, and iPhone 14 Pro Max today—all of which come preloaded with iOS 16.0.

Yesterday, Apple released iOS 16.0.1, which includes fixes for these problems.
After upgrading to the most recent version of iOS, problems with iMessage and FaceTime, according to Apple, should be fixed. Before you even get to the home screen, your brand-new iPhone can suggest an update as part of the first setup process. If not, after getting your iPhone 14, go to Settings>General>Software Update and update to the latest available version.
After updating to iOS 16.0.1, if you are still experiencing iMessage and FaceTime difficulties, you may need to make minor adjustments to the iMessage settings. Apple says to check Settings>Cellular and ensure your phone line is enabled.
Then, open Settings>Messages>Send & Receive. Tap the phone number that you want to use for iMessage. Open Settings>FaceTime and tap the phone number you wish to use with FaceTime.
If you follow those instructions, your iPhone 14 should usually be activated once more.