Comment 0 for bug 1734515

Setting "Automatically switch all running streams when a new output becomes available" breaks all audio. Setting from the System Settings -> Multimedia -> Audio Volume -> Advanced. After next boot the audio is gone. Pulseaudio refuses to start. And while the pulseaudio doesn't start up, the setting that caused this is now grayed out and can't be taken of. Leaving you with crippled system. This happens in Kubuntu 17.10.

The reason this happens, I believe, is that the setting puts the pulseaudio switch on connect module somewhere. And at least with 17.10 this is already defined in the pulseaudio configuration by default. Pulseaudio somehow doesn't like that t is defined twice.

I solved this by temporarily disabling the module from /etc/pulseaudio/default.pa, rebooting, switching of the setting from the System Settings and the re-enablig it from the /etc/. That is hardly something easy to do...