Video playback on 2nd screen issue

I am trying to watch BBC Iplayer on 2nd pc monitor (Acer 27" HD) my laptop is new Alienware 15 R3 with GTX1060 GPU.

I can watch BBC iplayer/YouTube in normal smaller size which is default, but when I select fullscreen in either BBC/YouTube the screen goes black but the mouse arrow is still visible.

The laptop plays fullscreen happily on its own screen but not on 2nd screen?