Try running an Office Repair:
I usually choose the Online Repair option, it's more thorough.
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I have Office Professional Plus 2016 and for a few weeks now I have been unable to insert page numbers into Word. When I click on "insert/Page Number/Bottom" all that appears is "Other Office.com page numbers".
Try running an Office Repair:
I usually choose the Online Repair option, it's more thorough.
I do not believe repair will help with this. (I could be wrong; it would not be the first time.)
This is a corrupted building blocks file.
See my page: Page Numbers not showing up.
https://www.addbalance.com/word/pagenumber10.htm#Solution
It give directions for replacing your built-in building blocks file.