Pushed the Nessus Agent 10.8.2 update through Intune and 4 of 14 failed with the error "The Windows Installer Service could not be accessed. This can occur if the Windows Installer is not correctly installed. (0x80070641)". I checked one of the affected hosts and the Windows Installer service startup type is manual and the status is stopped not disabled. Any idea why the MSI couldn't install on these machines? Let me know if I need to provide additional details.
I would try and reboot affected machines, if the update still fails to apply then try to manually install any MSI package to see if Windows Installer is working correctly.