Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
The issue is caused because NETWORK SERVICES (NS) lacks disk read write permission. I coppied the tmp msi installer from \windows\installers and ran it and got an error code. Went to \Program files\common files\Microsoft Shared\OfficeSoftwareProtectionPlatform
and gave NS permission. The on line installer installed Office but at 94%. Expect it a similar problem.
Seems like lack of permissions is the reason. In my case it was the Programdata folder.
Stuck at 94%. Simple reboot, and the installer finished up to 100%.