Summary:
In Config > Core > Translations. If save Chinese JSON string like:
{ "Hello": "你好" }
will be converted and saved to:
{ "Hello": "\u4f60\u597d" }
Resolution:
libphutil/src/parser/PhutilJSON.php
change line 132:
return json_encode($value, JSON_UNESCAPED_SLASHES);
to:
return json_encode($value, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);