Solved: The namespace cannot be queried. The RPC server is unavailable.

When setting up DFS for a client this weekend, I was met with this error:

The solution was to open the DNS control panel on a domain controller and remove the non-sensical A record for the root of the domain. In my case, 192.168.16.2 did not point to a domain controller, so I nuked it, after which I could create the DFS namespace.

‍

Hope this helps someone!