Check if you have issues on all your devices (phone, tablet, laptop, PC...) or just your TV.
Different manufacturers (Samsung, LG and others) have different operating systems on which their TV's run. Samsung uses Tizen while LG has webOS and they are not up to date with the latest standards in video playback.
That's why we developed a player which supports casting feature.
If the video is playable on your other devices, try casting it to your TV.