So I went ahead and found the release notes of Microsoft AutoUpdate and found that it can be downloaded and installed separately from Office itself. In contrary to others on the forum, it did not fix the issue for me. Hostname:~ user$ sudo launchctl load -w /Library/LaunchAgents/.plist Hostname:~ user$ sudo launchctl unload -w /Library/LaunchAgents/.plist Hostname:~ user$ sudo launchctl stop /Library/LaunchAgents/.plist Hostname:~ user$ sudo chown root:wheel /Library/LaunchAgents/.plist hostname:~ user$ sudo chown root:wheel /Library/LaunchDaemons/.plist The permissions of the AutoUpdate files should be root:wheel according to the post. While searching for a solution on the Microsoft Office forum, I found a post that mentioned to check the AutoUpdate file permissions in the LauchAgents and LaunchDeamons system folder and reload it. The MAU version that had the issues was v4.39 (September 14, 2021). This was really annoying, because Office apps kept notifying me of available updates after every restart of one of the Office apps. Now it did open the tool, but it looked like it failed updating itself and got stuck in the “Installing” state before it could update Office. Normally it starts Microsoft AutoUpdate (MAU) which searches for Office updates. A constant appearing message in Word and Excel about to “Check for updates” triggered me to start updating Microsoft Office on my Mac.

Office 2019 mac update