YouTube上传文件给我ArgumentNullException(C#)

我正在为YouTube服务使用谷歌".NET客户端库"
当我尝试上传视频时，我得到了错误。（System.ArgumentNullException）。

ArgumentNullException: Value cannot be null. Parameter name: baseUri

堆栈：

в Microsoft.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task)
   в Microsoft.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccess(Task task)
   в Microsoft.Runtime.CompilerServices.TaskAwaiter.ValidateEnd(Task task)
   в Microsoft.Runtime.CompilerServices.ConfiguredTaskAwaitable`1.ConfiguredTaskAwaiter.GetResult()
   в Google.Apis.Upload.ResumableUpload`1.<UploadCoreAsync>d__e.MoveNext() в c:'code'google.com'google-api-dotnet-client'default'Tools'Google.Apis.Release'bin'Debug'output'default'Src'GoogleApis'Apis'[Media]'Upload'ResumableUpload.cs:строка 459

我的代码：

X509Certificate2 certificate = new X509Certificate2(@"test.p12", "notasecret", X509KeyStorageFlags.Exportable);
    ServiceAccountCredential credential = new ServiceAccountCredential(
        new ServiceAccountCredential.Initializer("test@developer.gserviceaccount.com")
        {
            Scopes = new[] { YouTubeService.Scope.YoutubeUpload, YouTubeService.Scope.Youtube, YouTubeService.Scope.YoutubeReadonly }
        }.FromCertificate(certificate));
    if (credential.RequestAccessTokenAsync(CancellationToken.None).Result)
    {
        String AuthenticationKey = credential.Token.AccessToken;
    }
        var youtubeService = new YouTubeService(new BaseClientService.Initializer()
          {
              ApplicationName = "test",
              HttpClientInitializer = credential
          });
          var video = new Video();
          video.Snippet = new VideoSnippet();
          video.Snippet.Title = "Test Video";
          video.Snippet.Description = "Test Vide Description";
          video.Snippet.Tags = new string[] { "test" };
          video.Snippet.CategoryId = "22";

          video.Status = new VideoStatus();
          video.Status.PrivacyStatus = "private"; 
          var filePath = @"test.mp4"; 
          using (var fileStream = new FileStream(filePath, FileMode.Open))
          {
            var videosInsertRequest = youtubeService.Videos.Insert(video, "snippet,status", fileStream, "video/*");
            var uploadResult = videosInsertRequest.Upload();
            uploadResult = uploadResult;
          }

有人能帮忙吗？