Can't get the Training dialog to work (version 5.9)

[jandyman]

I've been messing about for hours trying to figure out how to get Audiveris to understand a music font it clearly doesn't understand. I've gotten a long way. I know how to get samples into the book repository, how to review them, and how to push to the global repository and see that they are there. I've looked at the documentation more than once. However, when I go to Train Classifier, and press Select, nothing happens. All the quantities in the dialog box are zero. What is going on?