Headings and numbering glitch(es) in MS Word for Mac 2015 Version 15.18 As in the attached screenshot image, my 4th level heading is inexplicably a block of solid black. This only appeared after sending the Word doc file as an Outlook attachment (!) also on the same Mac running El Capitan.

The formatting appears thus only for 4th level numbering - unfortunately I need the numbering to be linked to the heading style and so far the only way I found to get the numbers back is to change numbering / list style for that heading.


This was not added into the style as background/fill/highlight/etc.
It is clearly in the style as the screenshot shows, not in the doc content.


Anyone know where this glitch originates and how to revert?

Update: I managed to copy and paste the affected text into a new blank doc - the black blob remains even when you select "Use Destination Theme" as a Paste option. The field, whatever it is, appears to be recognized as a List Numbering object of some kind.
Finally I found an answer to this question. It appears to affect several versions of Word, because the fix at MS Answers appears to work on Mac Word as well.

Follow-up question: Anyone know if resetting the normal.dotm file on all PCs that need to access the affected docs would help avoid this in future? It's clearly something to do with invalid combinations of styles, formats etc. and maybe just using 1 common baseline would clarify the root causes?

Successor question [should I have asked this here?]

UPDATE: And... the problem returns upon saving (the corrected version) and reloading.