I am checking it. I will get back to you soon.

Hi pauldebbrata,

$(function () {
    $("[id*=gvFiles] .view").click(function () {
        var fileId = $(this).attr("rel");
        $.ajax({
            type: "POST",
            url: "Default.aspx/GetPDF",
            data: "{fileId: " + fileId + "}",
            contentType: "application/json; charset=utf-8",
            dataType: "json",
            success: function (r) {
                LoadPdfFromBlob(r.d.Data);
            }
        });
    });
});

Replace above code with below.

$("body").on("click", "[id*=gvFiles] .view", function () {
    var fileId = $(this).attr("rel");
    $.ajax({
        type: "POST",
        url: "Default.aspx/GetPDF",
        data: "{fileId: " + fileId + "}",
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        success: function (r) {
            LoadPdfFromBlob(r.d.Data);
        }
    });
});

For more details please refer below article.

jQuery event handler inside AJAX UpdatePanel not working after Partial PostBack in ASP.Net