I’ve been using mine for about the last five years, streaming MKV’s, AVI’s and MP4’s without any issues but recently some of those formats it just won’t play and says it’s unsupported. I never had this problem before, any reasons why this is happening all of a sudden?

Trouble with some MP$ and MKV's

Techflaws August 14, 2013, 4:43am 12

Hm, I could not find any

Muxing mode : Header stripping

in your pasted text. Also, this has been fixed quite some firmwares ago for all WDTV models.