FM 12 book does not show generated Table of Contents

I think that FieryPantone has hit the nail on the head, but another possible cause if you are using FM 2015 to work on your FM 12 book: Seit Update 13.0.3.1 funktioniert das Inhaltsverzeichnis erstellen nicht mehr.  Basic translation from German: After update 13.0.3.1, the TOC does not work.

Don't trust the translate button: "rumgefingert" means "fingered around with"  not "has been fingering".

I think he's having a slightly different problem than you, as he seemed to not be able to generate a TOC at all, and even on older documents, the TOC was broken. He had to uninstall completely and reinstall, just excluding that update.

Probably not the answer, but I think I could duplicate this behaviour :-} if you accidentally or even deliberately set a component (an ordinary .fm file or a generated file) to Exclude in the .book, that component will be:

• excluded when you generate a .pdf
• opened when you select File > Open all files in book

I think Find in book is another action that cheerfully ignores the Exclude flag.

And of course, the visual feedback to remind you you've excluded the component is, let's say, subtle ;-}