ios - NavigationController in swift leads to a black screen -

i'm trying use navigation controller identification process in swift code each time click on button leads it, shows following black screen:

here storyboard if can helps, there no warning , no error in code (using drag , drop segue or programmatically 1 leads same black screen)

probably segue picked: mode & transition.

are have single segue? possible have overlapping segues, not show in interface builder.

edit

is there way can see our segues?

1. open storyboard in new window
2. show document outline (leftmost pane)
3. show attribute inspector (rightmost pane)
4. select each view controller scene in document outline. segues listed @ bottom. can inspect identifier , segue in attribute inspector.