Why can't I update the GAL??

I'm trying to learn how to update the GAL so it will populate itself from Active Directory.

This image shows what happens on our Exchange 2013 server.

I'm using the command I read on umpteen websites and MS' own Exchange 2013 Help, what else am I supposed to configure??

I used this: https://technet.microsoft.com/en-us/library/aa998806(v=exchg.150).aspx

I get the same error if I add -DomainController switch.

Thank you, Tom