[M4D]

Try This:

pawn Код:

dcmd_w(playerid,params[])
{
    new string[128];
    if(!strlen(params))
    {
        SendClientMessage(playerid,COLOR_ERROR,"USAGE: /W (Message)");
        return 1;
    }
    for(new i=0;i<MAX_PLAYERS;i++)
    {
        if(IsPlayerConnected(i) && GetDistanceBetweenPlayers(playerid,i) < 10)
        {
            MyLabel = CreatePlayer3DTextLabel(playerid,params,COLOR_WHITE,0.0,0.0,0.0,40.0,0);
            Attach3DTextLabelToPlayer(MyLabel, playerid, 0.0, 0.0, 0.4);
            return 1;
        }
    }
    return 1;
}

your problem is "CreatePlayer3DTextLabel" Parameters.

pawn Код:

CreatePlayer3DTextLabel(playerid, text[], color, Float:X, Float:Y, Float:Z, Float:DrawDistance, attachedplayer, attachedvehicle, testLOS)

you forgot to add "testLOS"