无法读取属性＆＃39;长度＆＃39;未定义的Ajax数据表

Question

我的ajax调用返回后，我目前在浏览器中收到以下错误：

Cannot read property 'length' of undefined

这是我的HTML：

<table cellpadding="0" cellspacing="0" border="0" class="stdtable" id="dyntable">
<colgroup>
    <col class="con0" />
    <col class="con1" />
    <col class="con0" />
    <col class="con1" />
</colgroup>
<thead>
    <tr>
        <th>Id</th>
        <th>SerialNumber</th>
        <th>AccountCode</th>
        <th>ClientId</th>         
    </tr>
</thead>   
<tbody>       
</tbody>
</table>

这是JS：

  <script type="text/javascript">
    $(document).ready(function () {
        $('#dyntable').dataTable({
            stateSave: true,
            serverSide: true,
            searchDelay: 300,
            autoWidth: false,
            ajax: {
                url: 'Search',
                type: 'POST',                    
            },
            order: [[0, "asc"]],
            processing: true,
            columns: [
                {
                    "sName": "Id",
                    "bSortable": false
                },
                {
                    "sName": "SerialNumber",
                    "bSortable": true
                },
                {
                    "sName": "AccountCode",
                    "bSortable": true
                },
                {
                    "sName": "ClientId",
                    "bSortable": true
                }
            ]
        });
        // DataTables Length to Select2
        jQuery('div.dataTables_length select').removeClass('form-control input-sm');
        jQuery('div.dataTables_length select').css({ width: '60px' });
        jQuery('div.dataTables_length select').select2({ minimumResultsForSearch: -1 });
    });
</script>

最后是我的行动方法：

     [HttpPost]
    public async Task<ActionResult> Search(FilterRequest filter)
    {
        try
        {
            IQueryable<SerialRouting> filteredItems = db.SerialRoutings;
            if (!string.IsNullOrEmpty(filter.Search.Value))
            {
                filteredItems = db.SerialRoutings.Where(c =>
                c.AccountCode.Contains(filter.Search.Value)
                || c.Client.ClientID.Contains(filter.Search.Value)
                || c.Serialnumber.ToString().Contains(filter.Search.Value)
               );
            }
            int totalRecords = filteredItems.Count();
            filteredItems = filteredItems.OrderBy(x => x.Serialnumber);
            filteredItems = filteredItems.Skip(filter.Start).Take(filter.Length);
            var displayItems = await filteredItems.Select(x => new SerialRoutingViewModel { Id = x.SerialRoutingIdentity, SerialNumber = x.Serialnumber, AccountCode = x.AccountCode, ClientId = x.Client.ClientID }).ToListAsync();
            return Json(new PageResponse<SerialRoutingViewModel>(filter.Draw, totalRecords, displayItems.Count, displayItems.ToArray()));
        }
        catch (Exception ex)
        {
            Debug.WriteLine(ex);
        }
        return null;
    }

对于ModelBindings来自以下库：MVC.DataTables

我正在使用数据表v 1.10.10

我错过了什么？