Thanks for your help. It turned out that I was missing a JDK. I added that and it still did not work. Finally, I figured out that I had chosen Java 19 JDK which Ancestris does not support. So I added Java 17 JDK. Still did not work. Finally figured out I had to remove JDK 19 so Ancestris could see 17. That did the trick!
I know there were other ways to get Ancestris to default to JDK 17, but since I did not need JDK 19 anyway, I just removed it.
Now to start learning Ancestris!