Postby YeahThatCee » 13 Apr 2015 14:35
I know exactly what you mean: I own three Vizio smart TV's. I wasn't intending to sound like a smart aleck; it just came across that way because I was trying to indicate easy workarounds exist--but quickly gave an answer because I was watching Game of Thrones, lol!
Try this: simply rename the .mkv file on your thumbdrive to .mp4. (Depending on the audio or video codecs in the file, this will or may not work; you may only get video but no sound, for example, etc.)
The other HDMI cable, VLC format conversion, and hardware streaming options I'm sure you already know about: play through your laptop, Playstation, Roku, Apple TV, iPhone, etc.
It's not an impossible task; it's just a limitation of the Vizio's ability to not play or recognize all file formats.