How to identify the cause of an error in a release?

Question

Qt

I develop on QT 5.6 (Windows 10) for Windows XP.
On XP do not work out https requests (http) norms.
How can you somehow find out what's wrong? Maybe OpenSSL should be handed over or something else ... The
program does not give any errors.

Answer 1

Connect OpenSSL 1.0.x compiled statically and there will be no problems.
Or drag along with the exe file libeay32.dll and ssleay32.dll
https://slproweb.com/products/Win32OpenSSL.html
And if so, then check the root certificates.
If you need to connect to only one host, you can store the certificate in the resources of the CA program, or install the CA certificate in the OS as trusted.