I'm using Band-in-a-Box® for Windows Version 2018 (504)

I opened a new file and entered the notes by hand -- by clicking on the staff lines with my mouse. The third bar is the same as the first, so I used "copy - special" to copy the first bar to bar 3. After that it wouldn't let me change the number of bars per page. Closing the file and re-opening it doesn't help.