Google日历API -从服务器端获取事件停止工作-消息[Not Found]位置[-]原因[notFound]域[g

我从另一个用户管理的日历中检索所有事件，并使用服务器端库 google . api . calendar在我们的网站上显示它们。*。它继续工作良好，因为一段时间近2个月，突然停止工作，显示这个错误。问题是，服务帐户确实拥有日历中的所有权限(查看所有详细信息)，但在执行请求(request. execute ();)时莫名其妙地停止工作。有人知道这个问题的线索吗?我真的很感激。

public class GCalendarService : Service
{
    public GCalendarService(X509Certificate2 certificate, String accountName, String appName) : base(certificate, accountName, appName)
    {
        this.Scopes = new string[] {
            CalendarService.Scope.Calendar, // Manage your calendars
            CalendarService.Scope.CalendarReadonly // View your Calendars
        };
        this.InitializeCredential(certificate);
        this.GService = new CalendarService(new BaseClientService.Initializer()
        {
            HttpClientInitializer = this.Credential,
            ApplicationName = appName
        });
    }
    /// <summary>
    /// Gets all the events based on a period of time
    /// </summary>
    /// <param name="calendarId">The ID of the calendar to get the events</param>
    /// <param name="minDate">The minimun date to request</param>
    /// <param name="maxDate">The max date to request</param>
    /// <param name="maxEvents">The max amount of events to retrieve</param>
    /// <returns></returns>
    public Object GetEvents(string calendarId, DateTime? minDate, DateTime? maxDate, int maxEvents) 
    {
        EventsResource.ListRequest request = ((CalendarService)this.GService).Events.List(calendarId);
        request.TimeMin = DateTime.Now;
        request.ShowDeleted = false;
        request.SingleEvents = true;
        request.MaxResults = maxEvents;
        request.OrderBy = EventsResource.ListRequest.OrderByEnum.StartTime;
        return request.Execute();
    }

{
"error": {
    "errors": [
        {
            "domain": "global",
            "reason": "notFound",
            "message": "Not Found"
        }
       ],
    "code": 404,
    "message": "Not Found"
    }
}