I am requesting from iOS 9 device to https:// URL where iOS receiving error code -1202 "The certificate for this server is invalid. You might be connecting to a server that is pretending to be “example.com” which could put your confidential information at risk." Which already mentioned on
FYI : The same request is working on iOS 10 & 11 devices with 200 Ok Response. Also i have already handled the challenge methods in my HTTP Class using NSURLSession API.
Here Server is using self signed certificate.