I am aware that this question has been asked before and I had the solution working last week based on the responses in the answers provided, nothing has changed and all of a sudden the jquery has stopped working.
I am using an Ajax call (below) that returns me a string that I assign to a hidden link on a page to force the download of a file from my works LAN.
$(document).ready(function () {
$(".excelLoader").hide();
$('.extract')
    .on('click',
        function () {
            var rh = Number($(this.id).selector);
            console.log("clicked: " + rh);
            var loader = "load_" + rh;
            var excel = "excel_" + rh;
            console.log(loader);
            $("." + excel).hide();
            $("." + loader).show();
            var params = {
                responseHeaderId: rh
            }
            $.ajax({
                type: "POST",
                url: "SubmissionTracker.aspx/ExportFile",
                data: JSON.stringify(params),
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                success: function (data) {
                    $("#hiddenLink").attr("href", data.d);
                    console.log($("#hiddenLink").val());
                    $("#hiddenLink").click();
                    $("." + excel).show();
                    $("." + loader).hide();
                },
                error: function (data) {
                    console.log("error :" + data);
                    console.log(data);
                    $("." + excel).show();
                    $("." + loader).hide();
                }
            });
        });
})
the issue that I have now is that the href is not being set, so the click event fires but with nothing to fetch.
The line I believe to be the issue is $("#hiddenLink").attr("href", data.d);
 the line it is trying work with in my ASP.Net Webforms page is <a id="hiddenLink" href=""></a>. 
I have cleared my Cache, removed any temporary files that may have existed but still cannot reproduce the positive results I had last week.
Any and all help bery much appreciated.
-----------update----------------
issue appears to be on the click event of the link. JQuery that I am usering is version jquery-1.11.3.js which is referenced first, and the js file where this is referenced is in the middle of all the other referenced files.
