Windows Azure Development:禁止错误:服务器无法对请求进行身份验证

最近，我遇到一个Azure身份验证问题，错误消息如下：附加信息：禁止错误：服务器无法对请求进行身份验证。请验证证书是否有效以及是否与此订阅关联。

这是代码：

       private TokenCloudCredentials credentials;
        public ManagerClient(TokenCloudCredentials credentials)
        {
            this.credentials = credentials;
        }

        public void GetHostedServices()
        {
            var computeClient = new Microsoft.WindowsAzure.Management.Compute.ComputeManagementClient(credentials);
            var services = computeClient.HostedServices.List().HostedServices;
            foreach (var service in services)
            {
                Console.WriteLine("ServiceName: " + service.ServiceName);
                Console.WriteLine("Uri: " + service.Uri);
                Console.WriteLine();
            }
        }
        public static TokenCloudCredentials GetCredentials(string subscriptionId = "")
        {
            var token = GetAccessToken();
            if(string.IsNullOrEmpty(subscriptionId))
                subscriptionId = ConfigurationManager.AppSettings["subscriptionId"];
            var credential = new TokenCloudCredentials(subscriptionId, token);
            return credential;
        }
        private static string GetAccessToken()
        {
            AuthenticationResult result = null;
            var context = new AuthenticationContext(string.Format(
              ConfigurationManager.AppSettings["login"],
              ConfigurationManager.AppSettings["tenantId"]));
            result = context.AcquireToken(
              ConfigurationManager.AppSettings["apiEndpoint"],
              ConfigurationManager.AppSettings["clientId"],
              new Uri(ConfigurationManager.AppSettings["redirectUri"]));
            if (result == null)
            {
                throw new InvalidOperationException("Failed to obtain the JWT token");
            }
            return result.AccessToken;
        }
              var credentials = Authorizator.GetCredentials("37a80965-5107-4f9b-91c6-a1198ee40226");
              new ManagerClient(credentials).GetHostedServices();