The original tribes master server was shut down, and there is a new one now =)
Follow these instructions:
go to your tribes folder, then your config folder.. inside is a file called "ServerPrefs.cs"
open it, delete everything inside.. then, copy and paste this into it, and then save.. after that, you're good to go! =D
$Server::Address = "IP:24.127.46.93:28000";
$Server::AutoAssignTeams = "true";
$Server::CurrentMaster = "0";
$Server::FileURL = "http://www.planettribes.com/rpg/downloads";
$Server::FloodProtectionEnabled = "true";
$Server::HostName = "Your Server Name Here";
$Server::HostPublicGame = "false";
$Server::Info = "Welcome to the ServerName Server\nAdmin:Members\nEmail: Unknown";
$Server::JoinMOTD = "<jc><f1>Welcome to the ServerName Server:\nHave fun dont be a Dick!!\n\nFire to spawn.";
$Server::Master1 = "t1m1.masters.dynamix1.com:28000 t1m2.masters.dynamix1.com:28000 t1m3.masters.dynamix1.com:28000";
$Server::MasterAddressN0 = "t1m1.masters.dynamix1.com:28000 t1m2.masters.dynamix1.com:28000 t1m3.masters.dynamix1.com:28000";
$Server::MasterAddressN1 = "t1ukm1.masters.dynamix1.com:28000 t1ukm2.masters.dynamix1.com:28000 t1ukm3.masters.dynamix1.com:28000";
$Server::MasterAddressN2 = "t1aum1.masters.dynamix1.com:28000 t1aum2.masters.dynamix1.com:28000 t1aum3.masters.dynamix1.com:28000";
$Server::MasterAddressN3 = "t1m1.masters.dynamix.com:28000 t1m2.masters.dynamix.com:28000 t1m3.masters.dynamix.com:28000";
$Server::MasterName0 = "Community Master";
$Server::MasterName1 = "UK Tribes Master";
$Server::MasterName2 = "Australian Tribes Master";
$Server::MasterName3 = "US Tribes Master";
$Server::MaxPlayers = "8";
$Server::MinVotes = "1";
$Server::MinVotesPct = "0.5";
$Server::MinVoteTime = "45";
$Server::numMasters = "3";
$Server::Port = "28001";
$Server::respawnTime = "2";
$Server::TeamDamageScale = "0";
$Server::teamName0 = "Enemy's";
$Server::teamName1 = "Friend's";
$Server::teamName2 = "Children of the Phoenix";
$Server::teamName3 = "Starwolf";
$Server::teamName4 = "Generic 1";
$Server::teamName5 = "Generic 2";
$Server::teamName6 = "Generic 3";
$Server::teamName7 = "Generic 4";
$Server::teamSkin0 = "beagle";
$Server::teamSkin1 = "dsword";
$Server::teamSkin2 = "cphoenix";
$Server::teamSkin3 = "swolf";
$Server::teamSkin4 = "base";
$Server::teamSkin5 = "base";
$Server::teamSkin6 = "base";
$Server::teamSkin7 = "base";
$Server::timeLimit = "25";
$Server::TourneyMode = "false";
$Server::VoteAdminWinMargin = "0.659999";
$Server::VoteFailTime = "30";
$Server::VoteWinMargin = "0.549999";
$Server::VotingTime = "20";
$Server::warmupTime = "1";
$Server::XLMasterN0 = "IP:67.19.49.66:28000";
$Server::XLMasterN1 = "IP:216.249.100.66:28000";
$Server::XLMasterN2 = "IP:204.145.237.75:28000";
$pref::LastMission = "RaindanceLT";