Has nothing to do with your drivers.
FFXI use's the Direct X API, each version is specific and in this case it's 8.1. Microsoft stopped releasing binaries for DX8 back with Windows XP and instead DX9 emulates DX8 via a wrapper library, and on modern systems DX11 is emulating DX9, which is emulating DX8. This is why FFXI can act screwy and unstable for some people.
Chances are your OS is missing some of the wrapper DLL's that do all that translation. Here is the link to the DX9 binary which contains all the legacy DX components. I've never tried this on Windows 10 so YMMV.
June 2010 binaries, this is the most current version.
https://www.microsoft.com/en-us/download/details.aspx?id=8109
March 2009 binaries, some people need to use this because the June 2010 doesn't install right.
https://www.microsoft.com/en-us/download/details.aspx?id=19743