Outlook is now forced to restore its database and rebuild the index, etc. to the Desktop (to keep it around until the restore is successful) In my case, I finally found that ' alternative method 6' from that guide worked. This website seems to have the most comprehensive guides for troubleshooting this. With Mojave & Outlook 2019, however, I had to try many other methods.
With previous version I had success with the Repair tool that you mention. Outlook and macOS's Spotlight (the indexing app) have notorious problems working together.
