When the app is compiled with -L/subsystem:windows:5, there is no console available when launching, for example, by double-clicking the exe in windows explorer.
One place that causes an issue is dwthelper/ResourceBundle.d. In the constructor, there are calls to Trace(), which are just simple debug statements. I think it makes more sense to do the following:
debug import tango.util.log.Trace;
Then when you need to see debug statements, you can just do the following:
debug Trace.formatln("I'm a debug line");
