There can be multiple reasons that cause the error in your TOC in Word. These can be:
If your TOC has missing bookmarks; you might have deleted them accidentally.Many users get this error when using an automated TOC.The bookmarks are outdated.There are broken or corrupted bookmark entries.
Before starting with the actual solutions, make sure you are able to view the bookmarks as the default Word settings don’t show them. So, for that, go to File > Options and move to the Advanced tab. In the tab, scroll down to the Show document content section and enable the checkbox called Show bookmarks and then click on the OK button.
Now, if you get the bookmark not defined error, you try the below fixes to get rid of the error. Let us check out the solutions!
Fix Bookmark not Defined in Microsoft Word
You can fix Bookmark Not Defined or Error, Reference source not found problems when you update a field that has a broken link to a bookmark in Word. Here are the solutions that you can use to fix the error: Let us discuss these methods in detail!
1] Replace the missing bookmarks
If you have accidentally deleted bookmarks and the bookmarks are missing, you replace them with the new ones. Follow below steps to replace missing bookmarks: Launch Word and open the document in which you are getting a bookmark not defined error. Go to the Table of Content page and right-click on the entry that is showing the error. From the context menu, tap on the Toggle Field Codes option. Now, you will see a field code “HYPERLINK \ PAGEREF” in place of the TOC entry that was showing the error. Simply go to the Insert menu and from the Link section, click the Bookmark option.
A dialog window will open up where you need to create a new bookmark using its old name. Enter the bookmark name and click the OK button.
Repeat the above steps for all the problematic bookmarks. Once all of the corrupted bookmarks are fixed, try saving the document as PDF and see if the bookmark not defined error is gone.
2] Use Undo command
In case you created an automated Table of Content and immediately got this bookmark not defined error, try to restore original entries by using the Undo command. You can simply use the Ctrl + Z hotkey or click on the Undo button present on the top of the ribbon in Word.
3] Convert TOC to static text
If there are too many broken and corrupted bookmark entries in TOC, it will get hectic for you to fix each and every broken bookmark. In that case, here is a quick and easy method to fix it up. Try converting automated TOC to static text and then edit the entries manually. For converting Table of Content to static text, simply select the TOC and then use the key combination Ctrl + Shift + F9. Doing so will convert all the bookmark entries to static text. Now, you can edit all the entries as you want and eliminate the bookmark not defined error. 4] Update Table of Content (TOC)
If some items that refer to bookmark entries are not updated correctly, you might receive this error. So, force the Table Of Content to update and see if you still get the same error. To do so, right-click on the TOC and then select the Update Fields option. You can also hit the Update Table button that appears on selecting the TOC. Hope that helps! Now read: How to create, insert and move a Bookmark in Microsoft Word.
