Ive been having the same error and I saw this post elsewhere.
Im going to try it later.

http://jp.finalfantasyxiv.com/lodest...2/blog/159361/


Marvin Martian (Excalibur)

2013/09/14 10:57
Error 6025 fix
I was having this error then installed .net framework 4 and all update and no more error 6025 demon. Check your programs list if u have it uninstall and reinstall as it might be corrupt if u do have it do your updates after installation and u might not have to reboot