vb.net 2017 unable to insert Calendar event - vb.net

Question

I have looked at all the examples I could find and hobbled together the code below. The first time I ran it a web page asked if I wanted to allow my user to update Google calendar and then it asked me to select an account. After that it just sat there and my windows application never finished painting the screen and displaying the simple button I had placed on a form from which to run the insert calendar event. Now when I run the code it comes up, a small gray window appears and it just sits there. What am I doing wrong?
Imports System.Collections.Generic
Imports System.IO
Imports System.Threading
Imports Google.Apis.Calendar.v3
Imports Google.Apis.Calendar.v3.Data
Imports Google.Apis.Calendar.v3.EventsResource
Imports Google.Apis.Services
Imports Google.Apis.Auth.OAuth2
Imports Google.Apis.Util.Store
Imports Google.Apis.Requests
Public Class Form1
Dim service As CalendarService
Dim GRPS As IList(Of String) = New List(Of String)()
Sub New()
Authenticate()
End Sub
Private Function Authenticate()
GRPS.Add(CalendarService.Scope.Calendar)
Dim credential As UserCredential
Using stream As New FileStream("client_secret.json", FileMode.Open,
FileAccess.Read)
credential = GoogleWebAuthorizationBroker.AuthorizeAsync(
GoogleClientSecrets.Load(stream).Secrets, GRPS, "user",
CancellationToken.None, New
FileDataStore("Vanguard")).Result
End Using
' Create the calendar service using an initializer instance
Dim initializer As New BaseClientService.Initializer()
initializer.HttpClientInitializer = credential
initializer.ApplicationName = "Vanguard"
service = New CalendarService(initializer)
Return 0
End Function
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles
Button1.Click
InsertCalendar()
MessageBox.Show("Done")
Application.Exit()
End Sub
Public Sub InsertCalendar()
Dim CalendarEvent As New Data.Event
Dim SDT As New Data.EventDateTime
Dim A As Date = DateSerial(2017, 8, 11)
A = A.AddHours(10)
A = A.AddMinutes(30)
SDT.DateTime = A
Dim b As Date
b = A.AddHours(2)
Dim EDT As New Data.EventDateTime
EDT.DateTime = b
CalendarEvent.Start = SDT
CalendarEvent.End = EDT
CalendarEvent.Id = System.Guid.NewGuid.ToString
CalendarEvent.Description = "Test Event"
Dim list As IList(Of CalendarListEntry) =
service.CalendarList.List().Execute().Items()
service.Events.Insert(CalendarEvent, list(0).Id).Execute()
End Sub
End Class