Hi,
Just recently started receiving the above error when attempting to play mp4 files (codec mpeg-2 1280 x 720, AC-3) from my Plex server (0.9.16.6). MKV files seem to work fine. Tried downgrading my NVIDIA driver to previous version (didn't help). Other clients (Android, Xbox, Visio TV) seem to be ok. Tried uninstall of Windows Plex client and re-install - no help. Any suggestions?