After updating the iPhone, many have encountered and the FaceTime / iMessage or stops working properly avoiding we can do video calls or send messages. It is emphasized that this is a temporary solution as there software problems can only be fixed by Apple.
solution:
Turn off the iPhone data in the cell configuration and make sure it is connected to Wi-Fi.
Go to iMessage in settings to disable the messages.
Go to Settings> General> Reset> Reset Network Settings and here we must configure our network and re-activate FaceTime and iMessage to work again.