Yeah, not sure why it opened the way it did.
 
Still have no problem hearing the sidechain in the Gate.

I too can hear the audio when it's switched in the gate, but it's not showing on the meter or doing anything
 

i'll look closer.
It might take a few minutes.

On my laptop, I had to change the settings (from a preset) on the gate, to get it to work.

How do I re-install just the Sonitus stuff?  I've got Command Center running
 

I believe you will need to rollback SONAR and then run the update again.

I'm still struggling with this Sonitus problem--this is affecting many of my projects and I really don't want to have to go back to rebuild each of them from scratch.  Help please Mr. Wizard.  The sample project I uploaded behaves just like the problem I'm having. "Loading a preset" doesn't fix anything.  
 
When the sidechain works, it's great.  Anyone know a free (or cheap) sidechain ducker VST that I could use instead? 

Free side-chainable gate and compressor here. Molot is a popular choice, despite being overly complex and temperamental. There is also MCompressor from Meldaproduction, part of the free bundle.

thanks bit--I looked at the compressors you mentioned; I'm not seeing ducking, maybe as it's a gate-type function.  Molot looked like it could be configured to do most anything, but not today.   I'll have a longer look later.

Have a look at the PC4K-S Type Bus Compressor. Here is  a video on how to set it up https://youtu.be/tkWeQR4UJf0?t=2m14s