Google .NET客户端Youtube v3错误

尝试将视频上传到我的YouTube Channels 时出现以下错误：

System.ArgumentException: Precondition failed.: !string.IsNullOrEmpty(authorization.RefreshToken) 位于Microsoft.Runtime.CompilerServices的Microsoft.Runtime.CompilerServices.TaskAwaiter.ValidateEnd（任务任务）中的Microsoft.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess（任务任务），位于Microsoft.Runtime.CompilerServices的Microsoft.Runtime.CompilerServices.TaskAwaiter.ValidateEnd（任务任务） . 在c：\ code.google.com \ google-api-dotnet-client \ default_3 \ Tools \ Google.Apis.Release \ bin \ Debug \ output \ default \ Src \ GoogleApis \ Apis中ConfiguredTaskAwaitable 1.ConfiguredTaskAwaiter.GetResult() at Google.Apis.Upload.ResumableUpload 1.d__0.MoveNext（） [Media] \ Upload \ ResumableUpload.cs：第356行

The Code:

class Program
    {
        private const string SERVICE_ACCOUNT_EMAIL = "685082793570-acspgovnpo2dfmcb5fsqdu5e0q7pdmn1@developer.gserviceaccount.com";
        private const string SERVICE_ACCOUNT_PKCS12_FILE_PATH = @"97b6020dc5777485250124e25b788e4b8ed3324e-privatekey.p12";

        static YouTubeService BuildService()
        {
            var certificate = new X509Certificate2(SERVICE_ACCOUNT_PKCS12_FILE_PATH, "notasecret",X509KeyStorageFlags.Exportable);

            var provider = new AssertionFlowClient(GoogleAuthenticationServer.Description, certificate)
            {
                ServiceAccountId = SERVICE_ACCOUNT_EMAIL,
                Scope = YouTubeService.Scopes.YoutubeUpload.GetStringValue()            };
            var auth = new OAuth2Authenticator<AssertionFlowClient>(provider, AssertionFlowClient.GetState);

            return new YouTubeService((new BaseClientService.Initializer()
                            {
                                Authenticator = auth,
                                ApplicationName = "Drive API Sample",
                            }));
        }

        static void Main(string[] args)
        {
            var youtube = BuildService();

            var video = new Video();
            video.Snippet = new VideoSnippet();
            video.Snippet.Title = "Video title";
            video.Snippet.Description = "Video description";
            video.Snippet.Tags = new string[] { "tag1", "tag2" };
            video.Snippet.CategoryId = "22"; // See https://developers.google.com/youtube/v3/docs/videoCategories/list
            video.Status = new VideoStatus();
            video.Status.PrivacyStatus = "public";  // "Video privacy (public, private, or unlisted)";
            var filePath = "52224a59-2029-43fd-806b-efc434256c25.mp4";
            var fileStream = new FileStream(filePath, FileMode.Open);

            var videosInsertRequest = youtube.Videos.Insert(video, "snippet,status", fileStream, "video/*");
            var upload = videosInsertRequest.Upload();
            Console.WriteLine(upload.BytesSent);
            Console.WriteLine(upload.Status);
            Console.WriteLine(upload.Exception);
}
}

任何想法为什么会这样？
我正在使用Google的1.5.0.28972版.Apis DotNetOpenAuth版本：4.0.0.11165