is Xcode 7.3.1 not compatible with Mojave??
I believe the lowest you can go is Xcode 8.x if you're on Mojave.
See the Xcode wiki for compatiblity
I even fear you need XCode 9.
I believe the lowest you can go is Xcode 8.x if you're on Mojave.
See the Xcode wiki for compatiblity
I even fear you need XCode 9.