I’m having this problem for the first time today. I’ve used InDesign since version 1.0, and was an Adobe Certified InDesign Instructor for about 20 years. I’ve created many dozens of Books, with ToCs, and never had an unsolvable problem. Using a book, the ToC picks up info from the first 6 documents, but not the 7th. I’ve checked and rechecked the styles applied, removed and re-added the doc from the book, and done everything else (even things that shouldn’t make a difference).

I’m stumped, and would love to know if others have had this problem.

There is a dotted line around the object, but that’s because it’s a button. I was able to select the same object on other document pages, but not on the page where I needed to select it. I don’t think I’ve ever used the option to “prevent object overrides” and it was not applied to this object.
I was eventually able to select it after I reapplied the master page. I feel certain it’s a bug, but not sure how to replicate it.
Thanks for your suggestion, though!

I’ve been using the Convert Rows to Header for years, but today it’s working a bit differently. When I choose the option to Convert Rows, it changes the line breaks in the row text?! (InDesign 13.1 on Win 7) Has anyone else encountered this “feature”?