This also applies to SAB.
I had a song book in a Word document that appeared to be properly formatted, and when I added it to the App Builder, I selected the “Song Book” option, but when I tried to run the app, I couldn’t get past the beginning of the document. When I checked the App Builder, I clicked on the book in the tree on the left, and then selected the Song Index tab. Both Songs by Number and Songs by Title subtabs were entirely blank.
I saved the document as a .doc and then as a .docx. When I added that document to the App Builder, it worked normally.
Not sure what the bug was, but this fix worked.
The original document had been edited while on Google Drive. Weather it was edited using Google’s Docs editor or Microsoft’s Word editor for browsers, I’m not sure. Not sure if that could be a cause.