Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Yes, I did understand about the supplemental but the combo updater might fix the issue for you if you have done the incremental updater prior to the supplemental. I have OS X 10.8.5 (12F45) and had no problems updating Office.
I looked on Apple downloads and they have removed the combo prior to the supplemental being added. The link is exactly the same as 10.8.5 prior and after supplemental.
When the Microsoft updater checks the file for required software, if it's wrong it quits. Only Apple can fix this file. It's worth a shot to see if combo updater will fix the issue. It certainly doesn't hurt. It's only your time to download and run.