Windows 10, Finale 2014.5.  I've used the 'move layers' command many times.  But I've just imported a piece using MusicXML (which I've also done many times.  When I try to move one particular staff from Layer 1 to 2 it just dissappears.  It's there - I can go in and edit notes, and I can move it back to layer 1 OK.  It's as if I had 'Show active layer only' selected - which I haven't.  And if I DO select it, and switch to layer 2 view, it's still blank.