When I create a new project using the "Messages Application" template of Xcode 8 and try to run it on iOS simulator, I get the following error:
The request to openfailed.
The request was denied by service delegate () for reason:
NotFound ("Application "com.myDomain.MyApp" is unknown to FrontBoard").
You may want to check your scheme. The executable should be asked on launch (You want to select Messages app). Edit Scheme -> Info -> Executable -> Ask on launch (rather than MyApp.app)