A family of Microsoft word processing software products for creating web, email, and print documents.
Hi Anie,
According to the error message, this means that the target of the cross references is missing in this document. Generally, to fix it, you need to either delete the cross reference or re-create it so that it refers to the appropriate part of the document. As Stefan mentioned, it will be a time-consuming task.
Also, we welcome community members to share ideas about the situation if one has related experiences.
Sincerely,
George | Microsoft Community Moderator