In "older" versions of NX, when one was to show some hidden detail of a somewhat complex part, the trick was to use view dependent edit and set the lines to keep to say dashed, then set all other hidden lines to invisible using the View style - hidden lines = invisible.
This was maybe a little backward process but it was very reliable.
Then in NX9 (NX10?) there was a change in methods, instead of the above one was to first set the lines to keep to say dashed using View dependent Edit.
Then select the view - Settings - Hidden Lines - tick the Show referenced Edges Only.
Ok fine, i can accept that. It might be a more logical process to a new user.
BUT, If i by mistake think that i should set all hidden lines to invisible in this dialog, NX deletes all my view dependent edits, no warnings. Gone.
Same if I try different options in this menu, suddenly that view dep edit is gone.