SpotifyAPI-NET: ImplicintGrantAuth - Error 404

In #283 I had some problems with converting the proper Auth Code by @JohnnyCrazy from C# into VB.NET. But I think I handled it now. This is my Code now:

Private Shared Sub WebConnect()
   Dim auth As SpotifyAPI.Web.Auth.ImplictGrantAuth = New SpotifyAPI.Web.Auth.ImplictGrantAuth(clientID, "http://localhost:4002", "http://localhost:4002")
   AddHandler auth.AuthReceived, AddressOf AuthOnAuthReceived

   auth.Start()
   auth.OpenBrowser()
   Console.ReadLine()
   auth.Stop(0)
End Sub

Private Shared Sub AuthOnAuthReceived(ByVal sender As Object, ByVal payload As SpotifyAPI.Web.Models.Token)
   Dim api = New SpotifyAPI.Web.SpotifyWebAPI With {
       .TokenType = payload.TokenType,
       .AccessToken = payload.AccessToken
   }
   Dim profile As SpotifyAPI.Web.Models.PrivateProfile = api.GetPrivateProfile
   Console.WriteLine(profile.DisplayName)
End Sub

Unfortunately, I still have problems with this Auth. I added “http://localhost:4002” to the Redirect URIs in the Spotify Developer Center already. After starting WebConnect(), my browser says “Connection Failed”. When I change the parameter from auth.Stop(0) to authStop() or authStop(1000), the opened site just tells me “404 - Not Found”.

Whats wrong with my code?

EDIT: The AuthOnAuthReceived-Event doesn’t get triggered. Why?