[SOLVED] Plays no video except mkv files?

[IriDium]

No need to purchase a license yet.

Did that test file play correctly? If so, then it is the coding in your file that is at issue.

If not, then at least we have eliminated one point of error.

Or try as Richardo suggested - use SMB.

As another test, can you copy the file to a USB stick or something and play it directly from the RPi.