error occurred while sending a direct message

[ahmed dawod]

I have a problem authenticating my Google Calendar Application
I get this error message when I try to get the events

error occurred while sending a direct message

private void btnAuthorize_Click(object sender, EventArgs e)
        {
            try
            {
                // Register the authenticator. The Client ID and secret have to be copied from the API Access
                // tab on the Google APIs Console.
                var provider = new NativeApplicationClient(GoogleAuthenticationServer.Description);
                FullClientCredentials credentials = new FullClientCredentials();
                credentials.ClientId = data.appUser;
                credentials.ClientSecret = data.appPass;
                credentials.ApiKey = data.appAPI;
                provider.ClientIdentifier = credentials.ClientId;
                provider.ClientSecret = credentials.ClientSecret;

                var auth = new OAuth2Authenticator<NativeApplicationClient>(provider, GetAuthorization);

                // Create the service. This will automatically call the previously registered authenticator.
                service = new CalendarService(auth);

                Events results = service.Events.List("primary").Fetch();

                //if (auth.State == null)
                //    return;
            }
            catch (Exception ex) { if (state != null)txtAuth.Text = state.AccessToken; MessageBox.Show(ex.Message); }
        }


        IAuthorizationState state;
        private IAuthorizationState GetAuthorization(NativeApplicationClient client)
        {
            // You should use a more secure way of storing the key here as
            // .NET applications can be disassembled using a reflection tool.
            const string STORAGE = "google.samples.dotnet.siteverification";
            const string KEY = "y},drdzf11x9;87";

            // Check if there is a cached refresh token available.
            state = AuthorizationMgr.GetCachedRefreshToken(STORAGE, KEY);
            if (state != null)
            {
                try
                {
                    client.RefreshToken(state);
                    txtAuth.Text = state.AccessToken;
                    return state; // Yes - we are done.
                }
                catch (DotNetOpenAuth.Messaging.ProtocolException ex)
                {
                    //CommandLine.WriteError("Using existing refresh token failed: " + ex.Message);
                }
            }
            // Retrieve the authorization from the user.
            state = AuthorizationMgr.RequestNativeAuthorization(client, Scope);
            txtAuth.Text = state.AccessToken;
            AuthorizationMgr.SetCachedRefreshToken(STORAGE, KEY, state);
            return state;
        }