To be honest, at this point, jumping into the CPWizard rabbit hole is only recommended for the obsessive compulsive. I love CPW but I don't think it is supported anymore. For those of us who already have it set up, it would be a big hassle to switch to something else, so we're caught in a "sunk cost" situation trying to keep things working. However, if you are only starting now, you might want to see what else is out there.
At any rate, I had the same issue as you recently and was able to resolve it in this way:
1. Go to settings and check the box for "dynamic data loading"
2. Your preview list should now populate; if not, restart CPW
3. Once satisfied that the preview list is working, uncheck the dynamic data loading box again to revert to your original state
After that, the list should always be populated without having to go through that again. You will notice long pauses when exiting the settings screen after checking and unchecking those options.
I hope this works for you.