为什么ajax说在服务器上找不到404？

Question

Okey问题是我进行了ajax调用，当任何属性为null时，ajax都可以正常工作，但是当所有属性okey ajax都说“ 404 not found”时，有一个有趣的事情，该问题仅在服务器上发生。在我的本地主机上没问题。

 $(".add-button").click(function (e) {
    e.preventDefault();
    var id = "#";
    var langId = $(".select-language").val();
    id += langId;

    var realpartno = $(id+" .input-tags").val();

    var value = [];
    var newRealPart ="";
    for (var i = 0; i < realpartno.length; i++) {

        if (realpartno[i] != ",") {
            newRealPart += realpartno[i];
        }
        else {
            value.push(newRealPart);
            newRealPart = "";
        }
        if (i == realpartno.length - 1) {
            value.push(newRealPart);
        }
    }
    var formData = new FormData();
    formData.append("Description", $(id + " .description").val());
    formData.append("SubCategory", $(id + " .subcategory").val());
    formData.append("RealPartNos", value);
    formData.append("Categories", $(id +" .category").val());
    formData.append("Photo", $(id + " .product_photo").get(0).files[0]);
    formData.append("LanguageId", $(".select-language").val());

    $(id + " .error_view").empty();
    $(id + " .error_view").text("Zehmet Olmasa Gozleyin Sorgu Icra Edilir ...")
    $.ajax({
        url: "/Admin/Home/Add/",
        type: "post",
        dataType: "json",
        data: formData,
        cache: false,
        contentType: false,
        processData: false,
        success: function (response) {
            if (response.status == 200) {
                swal({
                    title:"Success",
                    icon: "success",
                    text: response.message,
                    buttons: ["Siyahiya Kec", "Yeni Mehsul Elave Et"]
                });
                ClearArea("#description");
                ClearArea("#product_photo");
                ClearElement(".input-tags .item");

                var a = document.createElement("a");
                a.href = "/Admin/Home/Index";
                a.innerText = "Siyahiya Qayit";
                a.className = "btn btn-success my-2";
                a.style.color = "#fff";
                $(id + " .error_view").empty();
                $(id + " .error_view").append(a);
            } else {
                swal({
                    title: "Error",
                    icon: "error",
                    text: response.errorMessage
                });
            }
        }
    });
})

为什么我的本地主机没有任何问题，只有一切正常时服务器上才有问题。这就是我的行为

[HttpPost]
    public async Task<JsonResult> Add(ProductViewModel model)
    {
        //Check All Models
        foreach (string item in model.Categories)
        {
            if (item == null)
            {
                return Json(new { status = 400, errorMessage = "En azi 1 category elave edin" });
            }
        }


        if (model.Description == "")
        {
            return Json(new { status = 400, errorMessage = "Description elave edin" });
        }

        if (model.SubCategory == "")
        {
            return Json(new { status = 400, errorMessage = "En azi 1 Subcategory elave edin" });
        }

        if (model.Photo == null)
        {
            return Json(new { status = 400, errorMessage = "Sekil elave edin" });
        }

        foreach (string item in model.RealPartNos)
        {
            if (item == null)
            {
                return Json(new { status = 400, errorMessage = "En azi 1 realpartno elave edin" });
            }
        }

        if (model.LanguageId == "")
        {
            return Json(new { status = 400, errorMessage = "Dil elave edile bilmir" });
        }




        //Find Language
        Language language = db.Languages.Where(l => l.Key == model.LanguageId).FirstOrDefault();
        var sub = model.SubCategory;
        var description = model.Description;

        //Make Category and RealPartNo Arrays
        List<string> categories = MakeArray(model.Categories);
        List<string> realPartNos = MakeArray(model.RealPartNos);


        //Upload Photo
        var photo = model.Photo;
        var file_name = photo.FileName;
        var path = Path.Combine(Directory.GetCurrentDirectory(), "wwwroot", "Uploads", "Products", file_name);
            if (MyFile.isImage(photo))
            {
                await MyFile.Upload(photo, path);
            }

        //Create Product
        Product product = new Product();
        product.SubCategory = await db.SubCategories.Where(s => s.Name == sub).FirstOrDefaultAsync();
        product.PhotoPath = photo.FileName;

        //Creat RealPartNo
        foreach (var realPartNo in realPartNos)
        {
                RealPartNo number = new RealPartNo();
                number.Name = realPartNo;
                number.Product = product;
                await db.RealPartNos.AddAsync(number);
        }


        //Create Category
        foreach (var item in categories)
        {
            if (item != null)
            {
                Category category = await db.Categories.Where(c => c.Name == item).FirstOrDefaultAsync();
                ProductCategory productCategory = new ProductCategory();
                productCategory.Category = category;
                productCategory.Product = product;
                db.ProductCategories.Add(productCategory);
            }
        }


        //Create MultiLanguage Product
        ProductLanguage productLanguage = new ProductLanguage();
        productLanguage.LanguageId = language.Id;
        productLanguage.Product = product;
        productLanguage.Description = model.Description;
        await db.ProductLanguages.AddAsync(productLanguage);
        await db.Products.AddAsync(product);
        await db.SaveChangesAsync();

        return Json(new { status = 200, message = "Mehsul Elave Edildi" });
    }