Uncaught TypeError: Cannot use 'in' operator to search for 'length' in

try {
    $AD = $pdo - > prepare("INSERT INTO tb_shop_prices_laposte_virtuel (Zone, Montant, NIC_Handle) VALUES (:VAL_Zone, :Poids_final, :VAL_Handle)");
    $AD - > execute(array(
        "VAL_Zone" => $VAL_Zone,
        "Poids_final" => $Poids_final,
        "VAL_Handle" => $VAL_Handle
    ));

    $sql = "SELECT Montant FROM tb_shop_prices_laposte_virtuel WHERE NIC_Handle = '".$VAL_Handle.
    "' ";
    //Récupère le montant total a afficher
    $Stat = $pdo - > prepare($sql);
    $Stat - > execute();
    $result["success"] = $Stat - > fetchAll(PDO::FETCH_ASSOC);
    //$result["success"] 		= $Poids_final;

    $SUP = $pdo - > exec("DELETE FROM tb_shop_prices_laposte_virtuel WHERE NIC_Handle='".$VAL_Handle.
        "' ");
} catch (PDOException $e) {
    echo "<div class='alert alert-warning'>".$e - > getMessage().
    "</div>";
    die();
}

function Montant_Livraison() {
    var VAL_Poids = $('#VAL_Poids').val();
    var VAL_Livraison = $('#VAL_Livraison').val();
    var VAL_Zone = $('#VAL_Zone').val();
    var VAL_Lieu = $('#VAL_Lieu').val();
    var VAL_Handle = "<?php echo $_SESSION_NICHANDLE; ?>";

    var VAL_Table;
    switch (VAL_Livraison) {
        case "SIVOP":
            VAL_Table = null;
            break;
        case "EXPRESS":
            VAL_Table = "tb_shop_prices_laposte";
            break;
        case "LA POSTE":
            VAL_Table = "tb_shop_prices_laposte";
            break;
        case "DHL":
            VAL_Table = "tb_shop_prices_dhl";
            break;

        default:
            VAL_Table = null;
            break;

    }

    var data = {
        VAL_Poids: VAL_Poids,
        VAL_Livraison: VAL_Livraison,
        VAL_Table: VAL_Table,
        VAL_Zone: VAL_Zone,
        VAL_Lieu: VAL_Lieu,
        VAL_Handle: VAL_Handle
    };

    $.ajax({
            type: "POST",
            url: "_montant_livraison.php",
            cache: false,
            data: data,
            async: true,
            dataType: "json"
        })

        .done(function(reponse) {
            var erreur = typeof(reponse.Error) != 'undefined' ? reponse.Error : null;
            var result = typeof(reponse.success) != 'undefined' ? reponse.success : null;

            if (!erreur) {
                if (result != null) {
                    console.log('Resultat', result);

                    var TAX = ""
                    var Poids = "";

                    $.each(result, function(i, vx) {
                        $.each(vx, function(colonne, valeur) {

                            var Taux = Number( < ? php echo $MNY_Taux; ? > );
                            var Pays = document.getElementById("VAL_Lieu").value;

                        });
                    });

                    $("#RCP_Frais").html("<?php echo ": ".$MNY_Symbole."
                        "; ?>" + Poids);
                    $("#VAL_Transport").val(Poids);
                }

                // ajouté pour le cas de SIVOP
                if (result == null) {
                    var Poids = "0";

                    $("#RCP_Frais").html("<?php echo ": ".$MNY_Symbole."
                        "; ?>" + Poids);
                    $("#VAL_Transport").val(Poids);

                }

                var transp = document.getElementById("VAL_Transport").value;
                var devise = document.getElementById("VAL_Devise").value;
                $("#Montant_Transport").html(devise + " " + transp);

            } else {
                alert('Erreur AJAX !');
                console.log('Erreur', erreur);
            }
        })
        .fail(function(jqXHR, textStatus) {
            console.log('Ajax error :', jqXHR, textStatus);
            alert('Erreur AJAX !');
        });

}

$VAL_Table = !empty($_POST["VAL_Table"]) ? $_POST["VAL_Table"] : NULL;
$VAL_Poids = !empty($_POST["VAL_Poids"]) ? $_POST["VAL_Poids"] : NULL;
$VAL_Livraison = !empty($_POST['VAL_Livraison']) ? $_POST['VAL_Livraison'] : NULL;
$VAL_Zone = !empty($_POST["VAL_Zone"]) ? $_POST["VAL_Zone"] : NULL;
$VAL_Lieu = !empty($_POST["VAL_Lieu"]) ? $_POST["VAL_Lieu"] : NULL;
$VAL_Handle = !empty($_POST["VAL_Handle"]) ? $_POST["VAL_Handle"] : NULL;

$result = array();

if ($VAL_Table == "tb_shop_prices_dhl") {

    $sql = "SELECT $VAL_Zone FROM $VAL_Table WHERE $VAL_Poids BETWEEN Poids_min AND Poids_max";
    try {
        $Stat = $pdo - > prepare($sql);
        $Stat - > execute();
        $result["success"] = $Stat - > fetchAll(PDO::FETCH_ASSOC);
    } catch (PDOException $e) {
        $result["Error"] = "<div class='alert alert-danger'>".$e - > getMessage().
        "</div>";
    }

}


if ($VAL_Table == "tb_shop_prices_laposte") {
    [...]
    //$result["success"] = $Poids_final;

    try {
        $AD = $pdo - > prepare("INSERT INTO tb_shop_prices_laposte_virtuel (Zone, Montant, NIC_Handle) VALUES (:VAL_Zone, :Poids_final, :VAL_Handle)");
        $AD - > execute(array(
            "VAL_Zone" => $VAL_Zone,
            "Poids_final" => $Poids_final,
            "VAL_Handle" => $VAL_Handle
        ));

        $sql = "SELECT Montant FROM tb_shop_prices_laposte_virtuel WHERE NIC_Handle = '".$VAL_Handle.
        "' ";
        $Stat = $pdo - > prepare($sql);
        $Stat - > execute();
        $result["success"] = $Stat - > fetchAll(PDO::FETCH_ASSOC);

        $SUP = $pdo - > exec("DELETE FROM tb_shop_prices_laposte_virtuel WHERE NIC_Handle='".$VAL_Handle.
            "' ");
    } catch (PDOException $e) {
        echo "<div class='alert alert-warning'>".$e - > getMessage().
        "</div>";
        die();
    }

}

echo json_encode($result);
exit();