That means the sound file of the character is either: 1) With a wrong name.
2) In a wrong direction (not inside the media folder).
3) Inexistent.
If the sound file is there (.snd extension), try changing it's name to vken.snd and putting it in a folder called "media" inside the char's folder. If it's not there, you can fix it, but the char will not have sound ¬¬