I came across this error on a newly created Windows Server 2012 R2 domain controller in a lab environment.
Launch cmd and run: setspn -L <hostname> You will see no entries for WSMAN/<hostname> or WSMAN/<FQDN>
Run ADSIEDIT.MSC Browse to Domain > DC=domainname > OU=Domain Controllers >CN=<HOSTNAME> Right click on CN=<HOSTNAME>, where <HOSTNAME> is the name of the server throwing the error. Click the Security Tab Click Add / “Network Service” Then check (X) to allow access to “Validated write to service principal name” Click OK
Restart the Windows Remote Management Service Re-Run: setspn -L <hostname> Locate entries for WSMAN/<hostname> or WSMAN/<FQDN>
You can also manually create the WSMAN SPN’s using setspn.exe.