Today, I tried to play a video with
.mkv extension using VLC media player but I was greeted with error message. The problem is that VLC does not have the right codec to play the audio. So, video will work but there will be no audio 😦
VLC does not support the audio or video format “undf”. Unfortunately, there is no way for you to fix this.
The fix that worked for me was to update VLC to latest version. I was using VLC version 2.1.5 and I upgraded it to 126.96.36.199. This solve my problem and I was able to watch and hear video.