I had this happen . Try unplugging the docking station and plugging back in . if you use the dock.
Tried that, tried rebooting w/ and w/o dock. Tried unplugging cables, tried only one external monitor.
Couldn't even get it to output correctly to a VGA source. Something is really messed up maybe I will do the refresh and reinstall all my programs, but yuck. This sort of nonsense pushes me back toward my Lenovo laptop.