It's common for the words Error! Bookmark not defined to appear in a table in place of page numbers. If this occurs, it's possible that you deleted one or more headings or TC entry fields from your document and then updated the table of contents using the Update Page Numbers Only option. You have three options:
Restore the heading in your document.
Delete the offending line from your table of contents manually.
Update the table of contents, and when Word displays the dialog box asking whether you want to update the entire table, choose the Update Entire Table option (thereby also removing any manual formatting or editing you may have added).
Another possibility is that you may have separated the table of contents from the material it was built from. For example, you may have copied the table of contents into another document, or you may have built a table of contents in a master document and broken the links to the subdocuments.
To create a separate document that contains only a table of contents, while preserving the accurate page numbering, do this:
Choose File, Save As to make a separate copy of your document.
Working in the duplicate file you just created, select your table of contents.
Press F9 to update your table of contents.
With the table of contents still selected, press Ctrl+Shift+F9. This eliminates the underlying TOC field but retains all the text it displayed, including page numbers.
Delete everything else in the duplicate document except the table of contents.
For more information about managing links between master documents and subdocuments, see Chapter 19, "Master Documents: Control and Share Even the Largest Documents," p. 653.
Occasionally, tables may contain incorrect page numbers. This may be caused by
Hidden text that was visible when you last updated your table of contents
Changes in margins or other document elements that affect page numbering
Make sure your document looks exactly as it should when you print it; then select the table of contents and press F9 to update it. Unless you've removed or added headings or TC entries, choose Update Page Numbers Only when asked how you want the table to be updated.
Occasionally, tables of contents may incorrectly include paragraphs of text from your document. If this occurs, search for the paragraph and make sure it is not formatted with a heading style or formatted with an outline level other than Body Text.
Often, this problem occurs when you place a line break (Shift+Enter) between a heading and the following paragraph, instead of a paragraph break (Enter).
For more information about outline levels, see "Applying Outline Levels to Specific Text," p. 635.
If you must format paragraphs in an outline level other than Body Text, but you still do not want them in your table of contents, one workaround is to delete them manually from your table of contents after you build it. Remember that when you update your table of contents, you must choose Update Page Numbers Only instead of Update Entire Table; otherwise, the paragraphs will reappear.