Whenever I have "Reduce client lag" checked, my game fatals while loading square. Now with their genius idea of removing almost all of the options in Lunia Options, you won't be able to uncheck "Reduce client lag"
So what you have to do is
1) Go to your Lunia folder > C:\ijji\ENGLISH\Lunia
2) Right click your Config xml file
3) Open With > Notepad
4) If you checked "Reduce Lag" it should say
<lagreduce value="1" />
Change the 1 to a 0
<lagreduce value="0" />
Created by derangedcow
http://www.luniasquare.net/forum/topic/2056-fix-you-might-fatal-with-reduce-client-lag/