I don't know whether or not the public release of navi binaries was always going to be a thing, but as a non-official view, I'd say that you were delivered a finished product, but a select few individuals decided to ruin it... "This is why we can't have nice things."
You should be able to create rooms as you would on the public server, but you will need to ensure you have the required permissions, this means either running the server as admin or running it from a non-UAC protected directory (documents, desktop, etc). This might not work on reflection, I think we need to investigate room creation. For the time being, you should be able to run multiple instances of the server by copying the binaries to another location, and changing the port in navserv.json.
Did you already install the Visual C++ dependency listed in the main topic?
https://www.microsoft.com/en-us/down....aspx?id=48145
That's unusual, it certainly looks like a permissions issue. I can't investigate right now but should be able to in 6-7 hours. Are you using some strange characters in username, password, email address etc? It could be that it doesn't support non-English standard characters (e.g accented characters and such). It's worth trying without those characters.