Ok, so from time to time this happens, it should not, but it does
Issue:
You open the local Administrator group and all domain user accounts is just SID numbers, (a few could actually be names, but that is not very common). It looks like this:
Solution:
I’ll guess there are many ways to fix this, but the Quick and Dirty is to:
– Disjoin the domain (don’t restart)
– Join back
– Restart
/mike
Share this:
Categories: Windows Server 2016
The Deployment Bunny 
You can skip a step by simply rejoining the domin you are in in step 1: Join the DNS name of the domain if the NetBIOS name of the domain is in the computer and tab; vice versa if the DNS name shows. You do not have to join a workgroup first.
I had the same symptoms, but in my case it was actually the netlogon service that was the culprit.
For one reason or another, the service had become stopped. This caused the Test-ComputerSecureChannel cmdlet to throw an exception when I used it, and investigating issue that pointed me to the netlogon service.
Once I started the netlogon service, Test-ComputerSecureChannel returned True and SIDs in the local groups were replaced by their proper domain names.