Enter the following command to disable the System Integrity Protection (SIP):.Here are the steps I followed to fix the issues:ġ/ Disable System Integrity Protection (SIP)Ĥ/ Wait long enough for indexing to complete (couple of hours depending on the amount of files on the HDD).ĥ/ Enable System Integrity Protection (SIP)ġ- Disable System Integrity Protection (SIP) Ultimately, I have found a way to address the 2 major issues that I reported :ġ/ Spotlight search not working after upgrade to macOS Big SurĢ/ Outlook for Mac - Search not working after upgrade to macOS Big Sur In fact, at step #3, I got a consistent error message ' Privacy List Error: The item couldn’t be added or removed because of an unknown error'. Rebuild the Spotlight index on your Mac: This recommendation from Apple Support did not work in my case: Unfortunately, they could not solve te issues.

I got Apple Support involved twice, with live troubleshooting sessions. I ran into similar issue since I upgraded to macOS Big Sur.