I have an issue using MSpectralDynamics. This video shows how you can apply ducking to different audio channels using a side-chain:
My problem: The narrator says to "activate a side-chain." And then he clicks on a button that I'm encasing in red boxes here:

Following the same process, here is what I see when I follow his instructions:

The button is missing.
What I've tried: I've looked up this problem and have found instances of other users also using Cubase 7 running into similar issues with other plug-ins. Their solution was to use the VST3 version instead of regular VST.
I reinstalled MSpectralDynamics to see where the VST3 files go. This shows the directory when all options of installation are selected (VST, VST3, AAX):

When I check the VST plugins directory, it's the same .dll file that I have in my Steinberg Cubase VST folder. So I tried uninstalling again and this time unchecking AAX and VST and ONLY selecting VST3.
When I did so, the two directories you see above appeared... but the VST plugins directory portion is blanked out, suggesting nothing installs there. Which leaves C:/Program Files/Melda Production/MSpectralDynamics64 8. If you look closely at the above image, you'll see I have that folder open in the background, showing the only thing inside that folder after installation is complete.
What am I doing wrong?
I'm running Cubase 7.5 full (soon to be 8 Pro) on a Win7 x64 platform.
The resolution: Space reserved for solution for users with same issues in the future.
