https://www.siliconera.com/ffxiv-6-1...s-1-0-and-1-1/

https://www.reddit.com/r/ffxiv/comme..._on_windows_7/

Due to the changes in TLS :

In order to better maintain the game's security, connections using TLS 1.0 and 1.1 will be blocked. As a result, the game client can no longer be launched on the Windows®7 and Mac 32-bit platforms.

you probably need to enable TLS 1.2 (especially if you get the "unable to complete version check" error after entering your login information).
is it related to this?