Arbortext Editor has a nice feature that enables you to check a document for various types of errors. To use this feature, go to the Tools menu and click Check Completeness.
If any problems are found, Arbortext displays a window that lists the errors. I usually find that my document contains a bunch of broken cross references.
Notice the first sentence in the upper part of the window: “Double click the left mouse button on any object in error to position the cursor at the point of error, or to cycle through occurrences of the error.”
This statement is not particularly helpful with respect to broken cross references. What you need to do is double-click the underlined phrase “show ids”. This action causes the IDs and ID References dialog box to appear. From there, look for any rows that have the word “MISSING” in the Element column.