Just started using a rented server and found an uninvited player joined our game half way through play. The server had a password so not sure how that worked. How do I set up a ban file to stop unauthorised users accessing private games repeatedly?
After a quick search it appears that there is a bug with the server password protection function, even if they get the password wrong they are still able to connect. My advice to you would be to temporarily ban those uninvited players who are connecting to your server.