When I upgraded bibleref module from 2.0.0 to 2.1.3, I started getting this error when saving a node with a Bibleref field: Value must be 1. This error is on the chapter part of the first Bibleref field.
The cause is that new fields field_chapters and field_verses are empty after upgrading to this version.
Add an update hook to set the chapter and verse ranges for all books, for sites which upgrade to 2.1 release series.
Needs review
2.1
Code