jQuery Grid Plugin - jqGrid

Using JQGrid in Mvc. Works perfectly during normal run. When trying to Unit test a controller action that has a grid in it, the AjaxCallbackMode throws a null exception. Code below :

var model = new FrequentlyOrderedItemsModel();

List<FrequentlyOrderedItem> items = this._AccountRepository.GetFrequentlyOrderedItems(userContext.Organization, userContext.CatalogName, userContext.Language);

var json = items.AsQueryable();

return model.Grid.DataBind(json);

The AjaxCallbackMode (which is read only) throws a null exception that causes the test to fail.