[Konstantinos]

That's not the only problem. You also use return in the loop instead of continue;

You must also check the Wepid because if you pass any out-of-bounds value in aWeaponNames, it's going to give a run time error: Array index out of bounds.

pawn Код:

dcmd_giveallweapon(playerid, params[])
{
    new Wepid, Ammo;
    if(sscanf(params, "ii", Wepid,Ammo)) return SendClientMessage(playerid, -1,"{FF0099}[ADMIN]{FFFFFF}/giveallweapon [Wepid] [Ammo]");
    if(!(0 <= Wepid <= 46) || (Wepid == 19 || Wepid == 20 || Wepid == 21)) return SendClientMessage(playerid, -1,"Weapon IDs: 0-46. 19/20/21 are invalid.");
    for(new i = 0; i < MAX_PLAYERS; i++)
    {
        if(!IsPlayerConnected(i)) continue;
        GivePlayerWeapon(i, Wepid, Ammo);
    }
    new string[128];
    format(string,sizeof(string),"{FF0099}[ADMIN]{FFFFFF}Everyone has been given a %s!",aWeaponNames[Wepid]);
    SendClientMessageToAll(COLOR_ADMIN,string);
    return 1;
}