I have this action result in a MVC 4 controller:

        [ComboDataSourceAction]
        public ActionResult GetMyResult()
        {
            var _myResult = _wcfService.GetMyResult();
            return View(_myResult.AsQueryable());
        }

_myResult is just a List<MyItem>:

    public sealed class MyItem
    {
        public int MyKey { get; set; }

        public string MyDescription { get; set; }
    }

Then I have a view like this:

@using Infragistics.Web.Mvc

<div id="MyCombo"></div>

@(Html.Infragistics().Combo("MyCombo")
      .LoadOnDemandSettings(pLoad => pLoad.Enabled(true).PageSize(25))
      .DataBind()    
      .DataSource(@Url.Action("GetMyResult"))
      .DataSourceUrl(@Url.Action("GetMyResult"))
      .ValueKey("MyKey")
      .TextKey("MyDescription")
      .Width("300px")
      .Virtualization(true)
      .AutoComplete(true)
      .FilterExprUrlKey("startsWith")
      .FilteringType(ComboFilteringType.Remote)
      .RenderMatchItemsCondition(ComboRenderMatchItemsCondition.Contains)
      .Render())

When I run the application I get this error message:

Error: Unable to get property '__count' of undefined or null reference

The examples provided by Infragistics are related to OData and Json, I have tested it and runs fine, but I don't use that in my project, I use WCF to get my data into the controller then return a view with that data. 

In the examples I see this thing:

responseDataKey: "d.results.Results",

responseTotalRecCountKey: "d.results.Count",

I understand that something similar is missed in my code but I don't know how to translate that when using Razor and my datasource.

By the way, I don't actually have a view related to the actionresult, the examples of Infragistics say you have to return a view but there are not any view source code for that in the examples, so I have no idea how that view is. Got it? ;) I just want to load on demand and reomotely the igcombo with data comming from a list converted to IQueryable or something the igcombo can manage. I use Infragistics Professional 2014 Vol. 1.

So, what's wrong with my code?