C# 403客户端上的错误。executeQuery（）

我正在尝试从Office 365站点检索一些信息。我在executeQuery调用中遇到不一致的403错误。这是不规则的，由IISReset解决。请帮忙

ClientContext clientContext = new ClientContext(Constants.SP_URL);
            {
                SecureString passWord = new SecureString();
                foreach (char c in Constants.SP_SERVICE_PASS.ToCharArray()) passWord.AppendChar(c);
                var cred = new SharePointOnlineCredentials(Constants.SP_SERVICE_ACC, passWord); ;
                clientContext.Credentials = new SharePointOnlineCredentials(Constants.SP_SERVICE_ACC, passWord);


                    Web web = clientContext.Web;

                    string docLibraryName = Constants.SP_PUBLISHED_LIB;
                    var list = clientContext.Web.Lists.GetByTitle(docLibraryName);
                    clientContext.Load(list);
                    **clientContext.ExecuteQuery();**

---

以下是获取客户端上下文和加载数据所需的内容。这将根据office 365中的SP Online对您进行身份验证。我不知道你怎么说我重置了我的IIS。除非连接到本地SP实例，否则这不适用

private void AutheticateO365(string url, string password, string userName)
{
   Context = new ClientContext(url);
   var passWord = new SecureString();
   foreach (char c in password.ToCharArray()) passWord.AppendChar(c);
   Context.Credentials = new SharePointOnlineCredentials(userName, passWord);
   var web = Context.Web;
   Context.Load(web);
   Context.ExecuteQuery();
}