I've recently purchased a new television a Vizio M422i-B1. It has the ability to stream different media from different sources, USB, DLNA server etc..
In the past I've run PS3 media server and I've used my PS3 to be the go between to stream to my TV. My new tv allows me to browse the contents of my server and play certain files, BUT.. It locks the TV up if I try and play 1080p MKV files.
I'm hoping there is a work around for this, or a fix to the problem.
You can try playing the file from a USB stick plugged into the TV. If it doesn't play then the TV doesn't support MKV. You will have to check with Vizio service as the manual doesn't list supported file types. There should be contact info for you country in the manual.