Call my DLL from a CLR Table-Valued Function not working

CREATE FUNCTION [dbo].[fnAddressCoordinates](@addressLine [NVARCHAR](MAX), @city [NVARCHAR](100), @state [NVARCHAR](2), @zip [NVARCHAR](15))

RETURNS TABLE (

[address] [NVARCHAR](MAX) NULL,

[city] [NVARCHAR](MAX) NULL,

[state] [NVARCHAR](MAX) NULL,

[zip] [NVARCHAR](MAX) NULL,

[lat] [DECIMAL](18, 6) NULL,

[lon] [DECIMAL](18, 6) NULL

) WITH EXECUTE AS CALLER

AS

EXTERNAL NAME [GoogleGeocodeAPI].[GoogleGeocodeAPI.GoogleGeocodeAPI].[AddressCoordinates]

GO

[SqlFunction(FillRowMethodName = "AddressCoordinates")]

public static System.Collections.IEnumerable AddressCoordinates(SqlString address, SqlString city, SqlString state, SqlString zip, SqlString Bla)

{

// Input

GeoCode Req = new GeoCode

{

address = address.ToString(),

city = city.ToString(),

state = state.ToString(),

zip = zip.ToString(),

latitude = 0,

longitude = 0

};

// Results

ArrayList resultCollection = new ArrayList();

resultCollection.Add(Req);

return resultCollection;