text: Q:
  
  .NET AdaptivePayment SDK: PaymentDetails() is throwing a ConnectionException (404)
  
  I am calling the AdaptivePaymentService.PaymentDetails() to get the payment details for a payment, and it is throwing a ConnectionException indicating 404.  In order to debug the issue, I downloaded the source for the AdaptivePayment SDK as well as the Core SDK and stepped through the code, specifically, right where the HttpRequest is executed in Paypal.HttpConnection.Execute().  
  It appears as if all configuration variables are being read from the web.config:
  
  The address in the underlying httpRequest looks correct:
  
  The payload looks correct:
  
  However, a WebException is thrown with the following response:
  <!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
  <html><head>
  <title>404 Not Found</title>
  </head><body>
  <h1>Not Found</h1>
  <p>The requested URL /cgi-bin/ppapi was not found on this server.</p>
  <p>Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.</p>
  <hr>
  <address>Apache Server at <a href="mailto:ppmtps@paypal.com">api.sandbox.paypal.com</a> Port 443</address>
  </body></html>
  
  Any help would be greatly appreciated.
  
  A:
  
  Since you have configured both ClientId/Secret and 3-token credentials (API username, password, signature) in your configuration, the endpoint has been detected incorrectly, giving the REST API higher preference. Please remove the client id / secret configuration and you should see the endpoint set correctly to https://svcs.sandbox.paypal.com/AdaptivePayments/PaymentDetails
  
  