Xcode not supported for iOS 11.3 by Xcode 9.2 needed 9.3

Question

Apparently, with the latest IOS update, my version of Xcode could not build due to the following error.

Could not locate device support files. This iPhone

Answer 1

I have the same problem, OS Sierra trying to run iPhone SE with 10.3 using Xcode 9.2 and I don't have the resources to update to High Sierra and Xcode 9.3.

Solution:

1. Find your friends who have Xcode 9.3
2. Ask them to right click on Xcode, Show Package Contents then navigate to Contents/Developer/Platforms/iPhoneOS.platform/DeviceSupport/11.3 (15E217)
3. Copy the 11.3 (15E217) folder to your old Xcode (9.2) with the same file hierarchy

Now you have Xcode 9.2 with iOS 11.3.

Answer 2

I have macOS 10.12.6

You can download Xcode 9.3 from https://developer.apple.com/download/
and extract the "11.3 (15E217)" folder from it

The fix really works.