Im really new to Cubase. I was working on a song this week and all of a sudden When I played it, I got no sound. (like everything was muted). I have all of the input signals and the click still works. Also if I add a new instrument track I can hear the audio from it.
Also when i load a new template or project the sound is fine. I don’t think that this is an interface setup problem.
Im wondering how i can get my tracks to have sound again. 
No idea as I am also getting this issue all of the sudden in Cubase Pro 8. One project just out of no where started doing this. I have audio tracks routed to busses and controlled with vca’s. If I re route these tracks to the stereo outs, the sound comes back. In another project I started it happened right away after adding a vsti. This project has no special routing to busses or vca’s yet. After clicking “deactivate all mute states” it came back. But this did not work on the other project. Still investigating as this has just started happening to me…
Yea i had to re route to the stereo outs and it worked. it was a pain as i had 300+ tracks to do lol Hopefully there is a quick fix and answer for this!
I found that taking out slate digital vmr which I had on all tracks did the trick. I re installed vmr and re inserted on channels now all is fine. So for me it was vmr in the first insert of all tracks causing rhe issue.
On the other issue of no sound, with just 2 vsti, slate ssd and omnisphere loaded meters indicating signal but no sound, if I select reset sll mutes, save, then close and reopen project, the sound comes back. unfortunately I have yo do this everytime I open this project. So far those are the only 2 projects giving me issues.
Project with just 2 vsti loaded…ssd and omnisphere…when I open It I have to select “deactivate all mute states” save and close the project and then reopen it. Then the sound comes back.
On the 40+ track project…I found out by taking out VMR which is on first insert in all tracks, tge sound cones back. So the routing is still intact. It has something to do with vmr or the first insert slot…go figure.