No VST Audio

Yesterday in cleaning up my Cubase 5 machine, I lost the project on the screen…but when I rebooted and brought up Cubase, then brought up the project, I found everything loaded as always, BUT…BUT I lost the audio on the VST’s…all VST operational controls work…you can see activity in the “on’s” lites in the VST …but when I moved a VST control …the control moves but no audio reaction…in the headphones…
In Mixer 3, I have Stereo IN and Stereo OUT…
MIXER 3 shows activity when I speak into the micro…
Cubase is fed by M Audio 192, and there are is activity on the in and out sliders.
There is one button that is not on…I saw this years ago but can’t remember the fix…
bill@kc4pe.com