In my partial view I need to traverse the content tree and retrieve a collection of nodes with a specific doct type alias.

Here's my partial view code...

@inherits Umbraco.Web.Mvc.UmbracoViewPage
@{
    Layout = null;
    string filter = ViewData["filter"].ToString();


    var root = Model.Root().Children().FirstOrDefault(x => x.ContentType.Alias == filter);
    var pages = root.Children()
        .Where(x => x.IsVisible());
}

Here's where I'm calling the partial view from my view... `@Html.Partial("ItemGrid", new ViewDataDictionary{{ "filter", "itemDetails"}})

I get this error when it tries to render my partial...

Value cannot be null. Parameter name: content

When I step through it, the Model is NULL here...

var root = Model