Update: Found another thread. Some older plugins are 32-bit and don't automatically install with the 64-bit version. Solved.
I need to try this because I did not see all the plugins that Mr. G talks about in his Sonar X1 Power book. I wanted to try Chorus(Mono) last night, but didn't see it in the list.
Originally I had X1 Studio, then upgraded to X1 Producer...perhaps that's why some don't display.