title: Error: Failed To Connect to Host Uri Using PayFlow Pro and ASP.NET 1.1
body: <p>We have a support website that we use to create custom orders for our customers. This website runs ASP.NET 1.1 and connects to PayPal using the PayFlow Pro API. </p>
  
  <p>We also have a customer-facing website that runs ASP.NET 4.0 and also uses PayFlow Pro for connectivity to PayPal. </p>
  
  <p>The customer-facing website is communicating fine with PayPal, but we're getting a "Failed to Connect to Host Uri" error from the support site. </p>
  
  <p>Furthermore, we have a test server set up to run the support site, and it is communicating with PayPal with no issues. The only difference that I can tell between the test site and the production support sites is that test is running IIS 7.0 while production is running IIS 7.5. All DLLs and configuration files appear to be identical. </p>
  
  <p>All of this started happening about a week ago, just after PayPal discontinued use of SSL. I would think it has something to do with the SSL switchover, but we have disabled SSL in IIS so I'm not sure where else to look. And why would the customer-facing site continue to work while the support site can't connect? They use the same infrastructure.</p>