I get the following exception running the SW pipeline on Mac when I hit the first keyboard character after changing resolutions:

dhcp-santaclara22-2fl-west-10-132-182-61:HiDPI jagraham$ jfx_j80_dev -Dprism.order=sw TestDPI
Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
at com.sun.glass.ui.Screen.notifySettingsChanged(Screen.java:276)

It looks like code that is trying to update the screen objects on the list of windows gets an NPE from getNativeScreen() on one of the set of Windows...

Note that the problem also happens if I move the mouse into the window - the first mouse event in the window will generate the NPE.