I have tried all the fixes above and none of them works permanently. I like many others was delighted to find the control shift S, but found as others did that once the document was saved, the fix was gone after reopening the document.
The solution has to do with understanding the bizarre method in which Microsoft implemented multilevel numbering for headings, which embodies both using the list style and the paragraph style for each heading, and most importantly, linking each level of the
list style to a level in the heading style. None of this is intuitively obvious.
For a new document, the first step is to set up the list files, after which the heading levels are formatted.
For an excellent step-by-step guide on how to do all this, here is the link:
http://shaunakelly.com/word/numbering/numbering20072010.html
It is a complicated process, and I have not utilized it on a complete document for all nine levels, but it seemed to work for my need for a quick and dirty fix.
BTW, utilizing these concepts, I was able to do a quick and dirty by following the steps for establishing the levels, associating them with the headings. Afterward I was able to correct, three different documents with the same phenomena, and also now am able
to change the format of the heading without ending up with the bizarre message "must be a number between one and 600" that I received in my previous attempts.
The only previous suggestion posted in this lengthy thread that will work as a quick and dirty fix is to save the document in Word 2003 format (i.e .doc) and limp along with editing the document in compatibility mode. But that really destroys the purpose of
upgrading twice since were 2003, with the loss of utilization of a number of features implemented since that time.
If this does not work for anyone, please let me know!
matrixunloaded