Okay, I have change /translations/zh_CN/ into /translations/zh_Hans_CN. And it works.
And I add a new translation file for chines.
But, it is not perfect yet. "Inbox" is not translated ---- This text comes from plugins.
So, my question currently is, how to translate plugins?
I'm new to flaskbb.
I tried to set my language into chinese, but almost nothing happeded except "4 hours ago" becomes "4小时前".
I checked messages.po, chinese support is fine. So It seems there is something wrong with flaskbb or its setting.
So, my question is, what's the correct way to do localization with flaskbb?