I have seen other threads about this but could not reply and I am struggling to work out how to fix this problem.
I have had my WD TV HD Media Player since last christmas and had no problems playing files, however every time I try and open any file now I get “unable to play selected file please refer to user manual to covert files” (or something to that effect). This is true of files I have played numerous times before.
Having read other threads I get the impression that it has something to do with trying to play a .mkv file with a compressed header… this is where I first got completely lost! Without sounding like a complete ■■■■■ how do I know which files are .wkv (would insert embarrassed emoticon here if I could even work out how to do that!) and if I can find out which ones are will deleting just those solve the problem as all of this “mkvmerging” and “muxing” sounds way too complicated!
If anyone has the patience to help a complete coputer illerate how to sort out this problem it would be much appreciated!
Many Thanks
The most reliable way to tell is by using the freeware program called “mkvinfo”
It’s available here:
http://www.bunkus.org/videotools/mkvtoolnix/downloads.html#windows
(assuming you have a Windows PC) as part of the MKVTools package.
When you check an MKV file with MKVInfo it will tell you if “Header Removal” compression is used.
If so, re-muxing them is really not so complicated when you’ve done it; it just sounds complicated. :)
Thank you so much for your reply. Having gone through all my files individually and looking at their properties I saw they were all .avi files so thought Id just have a go at resetting the factory settings and resetting the side button and deleting the .wd_tv folder (as someone suggested on another thread) and hey presto it is working again! I guess I must have already deleted the offending .mkv file.
I downloaded the .mkv toolkit and fix but no files came up on the box when I clicked the folder - would that be because there are no .mkv files or because I did it wrong? Would be helpful to know in case I have same problem in future. Many thanks again for your help 
If you’ve got MKVtoolnix already, you might want to download MKVFix.exe.
You can use it to scan your media folders looking for files that use compression in the headers, and have it fix them, instead of having to check each one manually.
I gave a quick runthrough of using it here: http://community.wdc.com/t5/WD-TV-HD/where-can-i-find-older-software-for-HD-MEDIA-PLAYER-Gen1/m-p/86907#M2533
