AutoComplete returning "TypeError: "".toLowerCase is not a function

[Kathleen]

I have a very simple strongly typed datasource that consists of Bills:
public class BillName
    {
        public string Bill { get; set; }
    }
And a very simple test case that returns these bills through a WebApi in MVC:

var dataSource = new kendo.data.DataSource({
            transport: {
                read: {
                    url: "/api/NavBillApi/GetAllBills",
                }
            }
        });
        
        $('#searchBills').kendoAutoComplete({
            dataSource: dataSource,
            filter: "startswith",
            dataText: "Bill",
            minLength: 1,
            //ignoreCase: false,
            placeholder: "Select ...",
        });

[HttpGet]
        public IEnumerable<BillName> GetAllBills()
        {
            var billList = _billsService.GetAllBillNames();
            //var x = billList.Count();
            return billList.AsEnumerable();
        }
I have tried every option on the datasource and AutoComplete widgets that I have found in the documentation.  If I uncomment ignoreCase: false, then I get the error: Uncaught TypeError: Object [object Object] has no method 'lastIndexOf'.
I am out of ideas.  Thanks for any help.

[Georgi Krustev]

Hello Kathleen,

 
The dataTextField property was not defined correctly in the AutoComplete definition. Check this jsBin demo, which shows how it should be defined.

Regards,
Georgi Krustev
Telerik