5.1 Configuration Not Playing Mono Tracks

Scenario 1
Input tracks: mono/stereo/5.1
Master bus: 5.1
Monitor set format: Stereo
Result: All good

Scenario 2
Input tracks: mono/stereo/5.1
Master bus: Stereo
Monitor set format: 5.1
Result: All good

Scenario 3
Input tracks: mono/stereo/5.1
Master bus: 5.1
Monitor set format: 5.1
Result: All playback fine, except mono tracks (even the Sound library mono tracks won't play back). Changing a mono track to stereo or 5.1 will bring it back. Changing the track back to mono stops it from outputting again.

[Peter Chamberlain]

please see

viewtopic.php?f=32&t=71894

Scenario 3
Input tracks: mono/stereo/5.1
Master bus: 5.1
Monitor set format: 5.1
Result: All playback fine, except mono tracks (even the Sound library mono tracks won't play back). Changing a mono track to stereo or 5.1 will bring it back. Changing the track back to mono stops it from outputting again.

Mono tracks actually output from the Center channel of a 5.1 setup. Are you not hearing anything because you don't have a center speaker in your setup? Do you see the meters of the Main Bus or Monitors moving?