Discourse Docsのトップメニューボタンのテキストがありません

[JammyDodger]

これは最近報告され、修正が適用されたと思います。

Navigation links added by plugins and theme components are missing

After upgrade to 2.9.0.beta5 4a240f6c90 the navigation links added by Discourse Docs plugin and Nav Links Component are no longer available. There is a placeholder for the links in desktop view and in the drop down menu in mobile view, but the title of the links is missing. Link to Docs is missing here on Meta too.

/admin/upgrade ページから最新版にアップデートすれば、問題は解決するはずです。