I don’t know exactly what sequence of events got me stuck in the start system upgrade menu. I can’t seem to exit the menu. I can twist knob1 to toggle between OK and Cancel. But there is no way of triggering the Cancel (other than resetting power, which I’ve resorted to doing!).
In case this info is useful, none of the button leds were eliminated when I was in this state. Maybe that indicates that the buttons got disabled for some reason.
Fixed in build 1965