no picture on 3 finger swipe

[bobniborg]

I have tried three finger swipe up to cast my screen to my tv using a DLNA WDTV. I get sound but no picture (wdtv is hooked up with HDMI cable if that matters). Any idea? I've used internet, youtube and a few other things. Gallery will give me an image on the tv after a few second delay but a video gives me a can't play video 318 message.