How to resolve iPhone 7 running iOS 13.1.2 not supported by Xcode 10.1? When trying to run my test app on my iPhone 7, I got this message: 


  could not locate device support files. 


This iPhone 7 (model 1660,1778, 1779, 1780) is running iOS 13.1.2 (17A860), which may not be supported by this version of Xcode. 

My Xcode is version 10.1. I tried to update Xcode to latest from App Store. It never works - the coloured ball keeps spinning. What I can do?
You need to have Xcode 11 installed for this to work. Xcode 10.x won't recognize iOS 13.

Try logging out and in of App Store app on your Mac. If it doesn't work you try restarting your Mac. If that fails too, attempt a reinstall of Xcode from the App Store.