Well, I'm no less confused. All the relevant Trainz exes have full access through the Windows firewall. Turning the firewall, and my antivirus, all the way off, made no difference either. I'm still getting the same errors.
Since you don't show a registered version next to your username, then it's difficult to give you exact answers. With that said, I am going to assume you are using T:ANE.
Log into T:ANE using the same login you are using to log into the forums. If you already have a user account, you should use that one. If you don't and T:ANE does not show next to your name, or cannot remember your previous login, contact the helpdesk from this link here:
The same advice goes for using Steam. Due to some server connection issues, N3V's servers don't always pick up the registration in Steam, so you will need to contact N3V helpdesk to resolve that.
Once your login issues are straightened out, My Trainz server will generate a user ID for you, which will be found in the Dev tab in the Trainz settings on the Launcher.