Xcode: Could not locate device support files

Actually, there is a way. You just need to copy DeviceSupport folder for iOS 7.1 from Older Xcode to the new one. It's located in:

/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport/7.1

If you don't have the 7.1 files anymore, you can download a previous version of XCode on https://developer.apple.com/download/more/, extract it, and then copy these files to following path

/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport/

Credit

I had a similar problem because the app store version was missing iOS 10.1 support in Xcode 8 and they haven't rolled an update yet. This caused the "Xcode: Could not locate device support files" problem. You can download the latest update https://developer.apple.com/download/ and it is more current and supports iOS 10.1 (14B72c).

I have Xcode 10.1 and I can not run my application on my device with 12.2 iOS version.

The easiest solution for me was:

1. Go with finder at Xcode location
2. Right Click -> Show Package Contents
3. Contents -> Developer -> Platforms -> iPhoneOS.platform -> DeviceSupport
4. Here you find a list of supported version. Choose the most recent one and copy(In my case was 12.1 (16B91))
5. Paste in the same folder(DeviceSupport) and call it with the version you need.(In my case was 12.2 (16E227))
6. Close Xcode if you have it open
7. Reconnect device if it was connected
8. Open Xcode and build

If this trick does not working, you have to get the versions from the new Xcode version.

But you can try, saves a lot of time. Good luck!

EDIT: Or you can download your needed device support from here:https://github.com/iGhibli/iOS-DeviceSupport/tree/master/DeviceSupport