The service account has insufficient privileges to register service principal names

Dear Friends

I am setting up3 tier using cloud VM's, NAV app in one server, IIS on the second server & RDS on the 3rd.

As mentioned in the documentation, Enabled the 'ServiceLogonAccount' to register SPN on itself.
But event view i get the below message

'The service account has insufficient privileges to register service principal names in Active Directory.
Account: Domain\ServiceLogonAccount
Service principal names:
DynamicsNAV/ServerName:7045
DynamicsNAV/Servername.domain.com:7045'

Then i register SPN for the said manually,
setspn -a DynamicsNAV/ServerName:7045 ServiceLogonAccount
setspn -a DynamicsNAV/Servername.domain.com:7045 ServiceLogonAccount

eventhough the same message appears on the Event Viewer after restart the service.


Can you please help me on this?

Thanks & Regards
Nasheer.