@Greg You probably have a duplicate choice name in one or more of your choice lists. This is a new error that was added because choices with the same name will be impossible to differentiate in analysis.
You will need to either remove the duplicate choices or add allow_choice_duplicates column
in your settings sheet and below that header write yes
.
This is a not great error message and there is an issue at https://github.com/XLSForm/pyxform/issues/373 to improve it.