If you are getting the error "iPhone USB" network interface has not been set up." when connecting your iPhone to a Mac, follow these steps to resolve.
1. Plug your iPhone into the computer.
2. Click on the Apple Menu and Open System Preferences>Network
3. Click on the Plus Sign to add a New Interface
4. Select iPhone USB from the Menu
5. The Service Name should auto-populate and can be left as is. If it does not, just use enter the same name as the Interface.
6. Click Create
7. Leave Disable unless needed checked
8. Click Apply