[FalconWingsX]

pawn Код:

SendClientMessage(playerid, COLOR_WHITE, string);
    format(string, sizeof(string), "You have changed the name of this faction to %s.", FactionInfo[id][fName]);

You are basically sending an empty string, you need to flip these.

pawn Код:

format(string, sizeof(string), "You have changed the name of this faction to %s.", FactionInfo[id][fName]);
    SendClientMessage(playerid, COLOR_WHITE, string);