m4a audio files play but with restrictions

[Griffiner]

Hi - With m4a (DASH) files from YouTube the file plays from start only and does not allow forward etc. The play time is also about double the actual file time The webm version file has no problems and VLC works perfectly. However when the m4a file is opened in Fission and saved as an 'copy' m4a the file works perfectly in VLC. I'm using 'YouTube video and audio downloader' in Firefox (latest) - 2013 27 "iMac OS X 10.11.6. Don't know if anyone else has had the same problem. I have FFmpeg but not yet installed correctly - 'terminal' phobia.

[kimiraikkonen]

I have an quite old VLC version and it cannot play M4A audio files downloaded from Youtube with DASH format. When i try opening M4A file, nothing happens with VLC and standard screen is shown.

Is there any tweak to play them or do i have to install new version?