How to migrate open id 2.0 to Open Id connect in asp.net 4.0

Question

I am implementing Google Open id authentication with this code:

        string discoveryUri = "https://www.google.com/accounts/o8/id";
        var b = new UriBuilder(Request.Url) { Query = "" };
        var req = openid.CreateRequest(discoveryUri, b.Uri, b.Uri);
        var fetchRequest = new FetchRequest();
        fetchRequest.Attributes.AddRequired(WellKnownAttributes.Contact.Email);
        fetchRequest.Attributes.AddRequired(WellKnownAttributes.Name.First);
        fetchRequest.Attributes.AddRequired(WellKnownAttributes.Name.Last);
        fetchRequest.Attributes.AddRequired(WellKnownAttributes.Person.Gender);
        fetchRequest.Attributes.AddRequired(WellKnownAttributes.Contact.Phone.Mobile);
        fetchRequest.Attributes.AddRequired(WellKnownAttributes.BirthDate.WholeBirthDate);
        req.AddExtension(fetchRequest);
        req.RedirectToProvider();

We have tried this solution: Google OpenId Connect migration: getting the openid_id in ASP.NET app

but received this exception:

An exception of type 'System.ArgumentNullException' occurred in Microsoft.Owin.Security.Google.dll but was not handled in user code

Please suggest the best answer for solving these issues.