I may be mistaken on this one, but I THINK the service account not being able to talk to AD can cause that problem too.
Might want to check that the SQL Service account can talk to the AD server.
The above is all just my opinion on what you should do.
As with all advice you find on a random internet forum - you shouldn't blindly follow it. Always test on a test server to see if there is negative side effects before making changes to live!
I recommend you NEVER run "random code" you found online on any system you care about UNLESS you understand and can verify the code OR you don't care if the code trashes your system.