I know it's none of my business what anyone does, but don't delete the lang0.pak. I may fix it now, but I'd say in a few hrs it'll be back up and running again without having to delete lang0.pak. I'd say their was a minor mistake or accident when updating the game. Like I said though, none of my business what you do :D
I copied the two .lang files from /pack into /localize/TAIWAN/pack and it allowed me to play the game. However, my font is all in squares. I do not have the Korean Font Pack installed so im assuming that it should be showing Korean in the TW DBO (because the .lang files from /pack are from the Korean version. It reads the localized/TAIWAN .lang files usually allowing it to display Chinese.).
Thats why a few posts ago a guy had his in Korean for some reason.