Invalid Device State - Xcode/iOS Simulator error

Question

Problem: I cannot simulate an Apple watch interface. Whenever I try and test my Apple watch app on the iPhone 6 simulator, Xcode successfully finishes and builds the app, at

Answer 1

First of all, just clean the project.

1. Quit your project.
2. Quit your Xcode.
3. Restart Xcode.

This happens to me when I have two different Xcode versions running at the same time. Hopefully this helps you.