As long as you can see the file, it probably doesn't matter how it is accessed, since you will only need read/execute permission to open the file
--in any case, could be Debian multimedia supporthttp://us.generation-nt.com/answer/vlc- ... 62311.html
Try another media player, see if that works, then check any VLC plugins being used ?
Also, if it is a dvd/cd fileset, you usually use Open disc from VLC to read that setinto that application and begin processing the files in the order the fileset requires: the application VLC manages that for you..
If you aren't doing it that way, you will have to identify the file type and see how or if it is supported by that application..