In my console after running rm app:
pm_live to enable ProMotion's live reload system.
=> "Live reloading of app/screens/**/*.rb, app/views/**/*.rb is now on."
=> "Live reloading of RMQ stylesheets is now on."
when I changed app/screens/**/*.rb,the simulator screen turn to black.
when I changed stylesheets ,the screen didn't change until I restart app.
why live_reload work bad?