App installation failed

Question

In Xcode 6 Beta 5, when I attempt to run my app after building, I receive an error dialog that says:

App installation failed

Answer 1

I got this error when using Xcode 9 beta, the problem was that I was trying to run an app on an iPhone 7 targeting armv7 instead of arm64.

This issue was not easy to track because I was building the app from Unity, so check the architecture configuration whenever you get this message.