The problems playing certain media files can be caused by this :
- There's a problem reading the file. Maybe you don't have enough privileges to read that file, the storage device is damaged or there are communication problems with the storage device.
- The media file is corrupted.
- The filters needed to play that kind of media are not installed. Install the filters as indicated in this page or install a different pack of DirectShow filters that support that kind of media files.
- The filter's configuration is incorrect. Install again the LAV filters. Check the Reset settings option and check all the formats while running the installer.
- There's a bug with LAVFilters. These filters are in development and maybe they have some unfinished features. Try installing other DirectShow filters.