Hello, I have a language problem with D3. My Bnet is in French. My D3 is configured in french. But since today it opens in English, even if it is configured in French in the parameters of the game. Do you have a solution to put my game in French. Thank you.
same here, my language was T chinese, but today open up game is English. Please fix.
I am seeing many reports about this on the Bug Report forum. There is a way to force the game to open in your language.
In the launcher go to Settings > Game Settings > Diablo 3 > Check the box next to “Additional Command Line Arguments”
For French type
-locale=frFR
For German type
-locale=deDE
For Spanish type
-locale=esES
Click DONE at the bottom right.
Click the Play button and it should launch the game in that specified language.
For Chinese, I am afraid I don’t know the language code.
I would try
-locale=twTW
EDIT
Hey all,
This is a known bug that our Diablo 3 team is aware of and working to resolve. In the meantime the workaround that MissCheetah posted should work to set the game language.
Edit: I’m seeing reports that the issue should be resolved now actually. I just tested it and switching the language in the Blizzard app did correctly switch it in-game. Make sure the Blizzard app is updated and try re-testing it without the command line argument.
For Traditional Chinese,
-locale=zhTW
Just in case, someone don’t know the locale code, they can find it in the {D3_Installation}\x64\D3Debug.txt, (32-bit client don’t have \x64) e.g.
PS: I had this issue yesterday, but today the problem gone.
It appears the issue has come and gone a couple of times over the last few days as it was first reported on EU three days ago…
This is what I am seeing too. Going to leave it in the known issues over on Bug report for now.
Thank you! I depend on you for pretty much anything related to the Asia Region 
Hi. this problem has been bothering me for a week, whatever I did it won’t go back to Chinese version. Even my Bnet is Chinese version but when I get into the D3 still English. I’ve reinstalled and tried all the methods you mentioned above, none of these worked. Can you plz help me to slove this problem?
@FatFeng,
This thread is 6 months old. Your problem should be unrelated to the OP. You should create your own topic.
Have you tried changing the language in-game or on launcher settings?
In-game: ESC > Options > Account > Language Selection
Launcher settings: 設定 > 遊戲設定 > 暗黑破壞神III > 文字及語言