That maxconnections is for how many people can be connected to your server at once.
Anyway, Are you using delta?
If so search for
Code:
for(int i = 0; i < server.playerHandler.players.length; i++){
Player p = server.playerHandler.players[i]; if(p != null &&
!p.disconnected && p.connectedFrom.equals(connectedFrom) &&
playerId != p.playerId && !connectedFrom.equals("localhost") && !checkLog("connect", connectedFrom)){
sM("Address in use!"); returnCode = 9; disconnected =
true; return; } }
And comment it out.