Yes! It was the shaders I was using. By disabling those, I am able to get the program to compile and run!

I know, it's in the manual. But ... I don't know, it helps to come here and put down my questions in a coherent form. It's like, public scrutiny will force me to ask the right questions, and that helps me know what to look for. Plus, now others who face a similar issue might be able to benefit from my efforts.