They haven’t updated the scaffolded app to be compatible with CB4 yet. The defaults really need to get updated now that 4.0 is officially released.
I think this will take care of pulling down the right stuff with:
box coldbox create app --installColdBoxBE
Or, you can replace your onApplicationStart() with:
public boolean function onApplicationStart(){
application.cbBootstrap = new coldbox.system.Bootstrap( COLDBOX_CONFIG_FILE, COLDBOX_APP_ROOT_PATH, COLDBOX_APP_KEY, COLDBOX_APP_MAPPING );
application.cbBootstrap.loadColdbox();
return true;
}