Rendering fails after php upgrade if file contains certain characters

[hyprdrm]

I upgraded php and Nextcloud, and everything seemed fine :)

...But some .md files don't work any more: when I try and open them with the app, it just says "false" (in either: editor, mixed or preview mode).

The problem seems to be caused by certain characters -

• these cause it to fail:❔ ℹ️ ⚠️
• these seem OK: 💡 🗒

Unfortunately, the .md files that make up my wiki contain all those characters... :-/

Am I missing a php module or a config setting or something?

Thank you in advance, and best regards.

---

• Ubuntu 20.04
• PHP 8.1.25
• Apache 2.4.41
• Nextcloud 26.0.8
• Markdown Editor 2.4.1

[hyprdrm]

FYI: The issue @ivarsg describes here (with files_texteditor i.e. a different Nextcloud editor) sounds similar: the entire contents of the file are replaced with the single word "false".

[hyprdrm]

{"reqId":"Vwq0F2MoqDxoDuOt80U6","level":3,"time":"2023-11-30T20:15:02+00:00","remoteAddr":"REDACTED","user":"REDACTED","app":"PHP","method":"GET","url":"/apps/files_texteditor/ajax/loadfile?filename=template+tech.md&dir=%2FDocuments%2Fnotes%2Ftech","message":"iconv(): Detected an illegal character in input string at REDACTED/nextcloud/apps/files_texteditor/lib/Controller/FileHandlingController.php#105","userAgent":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Safari/537.36","version":"26.0.8.2","data":{"app":"PHP"}}