@VamsiDev said in Online installer SSL handshake fail:

in linux how we can fix mirrors in linux can give me a solution to fix this

Like shown in the link posted in this thread: https://wiki.qt.io/Online_Installer_4.x#Selecting_a_mirror_for_opensource

@DanBar said in Problem with OpenSSL 1.1 after Qt update?:

If so, how can I make my application compatible with OpenSSL 1.1

It should be enough to just link to it during build and then make sure proper DLL files are in the same directory where your .exe is built. Which DLLs you need and what file names they are depends on compiler used and Open SSL version - sorry I don't remember them exactly, I use Windows only sporadically. If I recall correctly there used to be 2 DLLs in old versions, but nowadays it's a single file and it's called something like libssl-1_1-x64.dll.

or is there a way to switch back to OpenSSL 1.0 to test and see if this is the issue?

OpenSSL 1.0 has reached end of life a long time ago. DO NOT USE IT, it is a serious security risk at this point.