I opened my FrameMaker 12 book, and then used Open all files in book. The table of contents is included in the open files, but does not show up in the book (and is left out of my PDF). I cannot Add the toc file, because it says it is already in the book. I could delete and regenerate, but I've done this a several times and I would like to solve the issue. I don't understand why the table of contents (file reference) disappeared from the book, although the file is open and obviously associated with the book.
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 ;-}
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.