I really wish someone is able to figure out why some people always get this error after every updates.

Things we (the unfortunate ones) knows:
A - Auto-update with Launcher, will get version error everytime after inputting ID, Pass and click Log In.
B - Fixed by using other's people boot folder.

Further testing.
(I) Deleting FFXIV folder from My Games in My Documents folder, does not resolve this problem.
(II) Auto update with Launcher. Launcher finish updating, close it. Open boot folder, replace one file "ffxivlauncher.exe" with someone's working "ffxivlauncher.exe". It works.

Conclusion. "ffxivlauncher.exe" seems to be the problem. I've tried comparing this file (from auto-update), with the one I got from others... I couldn't see any difference.
To me both files is exactly identical in size.

That's the only thing I found out. Hopefully someone else might shed some light. It's really annoying getting a working .exe file every time after an update.