I updated Freejoin with better compatibility for newer AC versions and also some improvements and new features. On the server side race now ends correctly a set time after the first player is finished, track+car config cycle is configurable and the server has administration commands.
Get the updated version from here. The client and server are compatible with the old version as well. For running a server check the server setup guide on that page, the process is somewhat different now.
edit: I did a quick update to version 1.22, on client it fixes all servers being displayed as password protected and on server sessions are automatically added/enabled/disabled depending on cycle setting.