I bought an new LG webOS 43LF63 smart tv.
When I want too look at a MKV/SRT file, I get English subs instead of Dutch. I know where i can change this on a PC, so I start searching and I found where the subtitle track button is located, only this button is not active, I can't use it and therefore I cannot change the language settings.

I attached a photo I took from the TV, does anyone knows how to change the subtitle track from English to Dutch?