When you're not logged in, visit [[ https://minecraft-zh.gamepedia.com | Minecraft Wiki (ZH) ]] with this header part `accept-language: zh-CN,zh;q=0.9` will cause a situation that system messages on the whole page displays in English, instead of the expected Simplified Chinese (zh-cn or zh-Hans-CN). This problem also occured on [[ https://files.lakejason0.ml | my own wiki ]], with MediaWiki version 1.35.1. Only system messages that contains a `/en` subpage are affected.
This problem can cause a severe readability issue on Chinese sites.
It's reported by Traditional Chinese users that this kind of header part `accept-language: zh-TW,zh;q=0.9` doesn't run into this problem, and will correctly show system messages in Traditional Chinese.
Currently, there's a workaround that by manually changing (or creating) the `/zh-hans` or `zh-cn` subpages, thus idk whether it's really related to Language Converter.