I'm working on a outline TOC for pdf output. For each chapter break, I'm using a single topic that contains the text "Chapter" and the System.ChapterNumber variable.
Capture of the Chapter.htm topic setup:

Capture of the Chapter.htm topic used repeatedly in the outline TOC:

I have set a new chapter break on each entry where the Chapter.htm topic introduces a new chapter in the TOC, and have set the Chapter Number for each break. However, when I generate the PDF, the Build Progress window shows the following errors:

A chapter in the pdf output looks like this:

Why isn't the System.ChapterNumber variable picking up the chapter number I specified for each chapter break? Am I missing a step?