Windows Server 2016 OS corrupt after UAC errors

Question

Hi colleagues,

In a matter of weeks, 2 separate virtual machines having WS 2016 got corrupt and completely unusable after a strange error (example attached) which manifests on task scheduler, IIS,mmc apps.

We found out that the issue was related to User Access Control policy which claimed that it has to be enabled but actually, we checked and it was already enabled on our machines. We ran force enable in PowerShell which required a reboot, moment after which the OS became inoperable. Startup repair or other debug also threw errors.

Any idea why this happens?

Thank you,