Error backing up iphone with itunes
I cannot back up iPhone 7
Error message: "the iphone Cannot be updated. An unknown error occurred (error code 4000")
I have Windows 10, iphone 7 with latest version of ios 12.1 and iTunes.
I have rebooted both devices several times with the same result.
Any guidance or suggestions would be appreciated
iPhone 7, iOS 11.0.1