You have no device configured for Master output, maybe that's the reason.
Even if you don't use the master output for anything, please configure it with any device you have available (maybe the HDMI output or something that has no speakers attached).
Then try again.
You have no device configured for Master output, maybe that's the reason.
Even if you don't use the master output for anything, please configure it with any device you have available (maybe the HDMI output or something that has no speakers attached).
Then try again.