No sound output under any system, DSP at 0%

I am on Pop!_OS 22.04 LTS, running Ardour rev 6.9.0~ds0-1build1 usually with Jack on 1024 Samples.
I finished editing my Podcast earlier today, shut off my PC and did some stuff. When I came back, started it up again and wanted to export the Podcast I noticed that the file Ardour produced was completely silent.
So I looked around a few things, changed the audio systems to pulse and alsa to see what happens. with logging out and back in between all changes.
Any other project I made still works, plays and exports fine. I even compared the preferences window tab for tab and it is the same.
There are no error messages appearing in that project in the ardour log, the volume bars for the individual tracks move, the master one does not move and the volume bars on the top right also do not move. whatever I choose the DSP indicator always sits at 0%

Please help, what did I do wrong?

Do you have your master bus connected to proper output device? Sorry for this stupid question. :crazy_face:

I don’t know. How do I check that?

If other projects work, I suppose audio routing is the cause.
Check the tracks if their output is set to Master, and Master bus to audio device.
Disconnected tracks and busses have “-” in the output button.

image

The broken project has a minus there. But the other working projects also have a minus there

post a screen shot of your mixer window. also hit Alt+P to open your Audio Connections. Set the Y axis to Busses and the X axis to Hardware and post that screen shot as well.