With one of the Automatic Tables of Contents I see something like the following essentially on a mouse over.
Here is the same thing without the Content Control.
In either case, all it means is that you are back at the Table of Contents.
To ditch the Content Control, delete and recreate your TOC using Custom TOC.
To update a Table of Contents that does not have the Content Control, you can...
- Press the F9 key when you are in the TOC,
- Right-click and choose Update Field,
- or Choose Update TOC in the Table of Contents menu on the Review tab.