Server Error in '/' Application.
The remote certificate is invalid according to the validation procedure.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.Security.Authentication.AuthenticationException: The remote certificate is invalid according to the validation procedure.

Source Error: 
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

<servicePointManager
          checkCertificateName="false"
          checkCertificateRevocationList="false"         
      />

ServicePointManager.CertificatePolicy = delegate { return true; };
или
ervicePointManager.ServerCertificateValidationCallback += delegate { return false; };

и уже другая ошибка
System.Net.WebException: "Удаленный сервер возвратил ошибку: (500) Внутренняя ошибка сервера."