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

I have Xcode 7.3 and Xcode 8.0 Installed.

If a am working with Xcode7.3 and opens Xcode8.0 to get some code from Xcode8.0 project.

When i run my application on Xcode7.3 So it will give me same error.

Solution is simple ForceQuit or Quit all Xcode's and open the required one.