If you create a new iOS Single View App project in Xcode 11, the generated boilerplate code is not compatible with iOS versions earlier than iOS 13, because it assumes the new SceneDelegate API is available.
What follows are the steps needed to make the application compatible with iOS 9 and later.
For a Swift app:
- In the target's General properties, set the deployment target to iOS 9.0.
- Remove the
SceneDelegate.swift
file from the project.