Plex team please see these threads. Plex app on some Samsung Smart TV’s will not play videos that are in MKV container any more (saying something along the lines of “Unsupported media”)
First thread:
**Please note that the topic of this thread is the certificate error - but scroll down past some of the responses and you will see people complaining about this Unsupported Media problem. We are unsure if the 2 are related but it’s been a few weeks and we haven’t seen any response. So I wanted to create a fresh thread to get some attention to this problem.