Error message "Field empty" when opening a PDF-file #13816

Steps to reproduce

1. Select an email with a PDF-file as attachment
2. Click on attachment to open the PDF directly in Nextcloud
3. Get error message "Field empty"

Note: opening a PDF-file in Nextcloud works as expected.

Expected behavior

Opening the PDF-file in Nextcloud environment.

Actual behavior

3. Get error message "Field empty"

Note: opening a PDF-file in Nextcloud works as expected.

Mail app version

5.12.4

Nextcloud version

35.0.1

Mailserver or service

Synology Mailplus

Operating system

Container running on Container Manager on a Synology NAS (DS225+)

PHP engine version

None

Nextcloud memory caching

No response

Web server

None

Database

None

Additional info

Opening the PDF-file in the Synology Mailplus client works as expected.