[Schock]

Its fixed :

Code:

public OnPlayerDeath(playerid, killerid, reason)
{
	if(GetPlayerWeapon(killerid) == 38)
	{
		new string[128], player[MAX_PLAYER_NAME];
		GetPlayerName(playerid, player, sizeof(player));

		format(string, sizeof(string), "%s died! Server Banned his attacker (reason: Minigun)", player);
		SendClientMessageToAll(YELLOW, string);
		Ban(killerid);
	}
	return 1;
}

this should work fine