Having troubles playing mkv files

i just bought the WDTV live streaming and set it up with my external harddrive. I was able to play other media files, then i tried a mkv 264x264 and that wouldnt work , and then any video i tried to play after that will not(not even the original filethat played).I have reset and am able to play the original file again but dont want to have to reset every time . I also dont see all the videos i have on my harddrive appearing on the screen.

thanku for any help u are able to provide

See this similar thread some of us have been replying to at the moment – it may give you insight to your problem:

WD TV Play and MKV filesYES or NO? - Western Digital Community

              

Its likely that one of your files is ‘bad’ and whenever that happens the player will hang-up and refuse to play any file even good ones. You will have to find out which one is ‘bad’ and not play it or re-encode it so that it is OK. Hardware like the WD Player is not very tolerant when it comes to video encoding. Saying that it really should not cripple the player but unfortunately it does.

What other files don’t you see?