Bug Report – Error Opening Word Files from iOS App

App version: 7.1.7
iOS version: 18.6.2
Device: iPhone SE

Nextcloud server version: (e.g. 28.0.5, hosted on TrueNAS)

Description of the issue:
When accessing the Nextcloud iOS app, everything works fine until trying to open a Microsoft Word document.
As soon as the file is opened, an error message appears (see attached image).
This only happens with Word files — PDFs and other file types open normally.

Steps to reproduce:

Open the Nextcloud app on iOS.

Search for a document (Word file, .docx).

Tap to open the file.

The app shows an error message instead of opening the document.

Expected behavior:
The Word document should open correctly in preview mode or the default associated app.

Actual behavior:
The app displays an error message (attached screenshot) and cannot open the file.

Additional info:

The same document opens normally from the web interface and desktop client.

The issue persists after reinstalling the app and clearing cache.

This issue occurs only on iOS.
The same document opens correctly using the Android Nextcloud app and from the web interface via OnlyOffice.

Start by reproducing the failure in the Nextcloud iOS app 7.1.7 on iOS 18.6.2 with a .docx file, then compare it with PDFs and the Android or web clients. Done means Word documents open in preview mode or the associated app without the reported error.