Issue Summary

Attachments opened from Confluence page view mode display the filename as "unknown" in Media Viewer and downloads with the filename "original" instead of the actual attachment name.

The issue is reproducible across multiple pages in the affected tenant. This issue has only been observed with some migrating customers. The attachment preview loads successfully, and attachment metadata appears to be intact within Confluence. The issue only affects the Media Viewer experience.

Note: The same attachments open and download as expected from the page attachments.

Steps to Reproduce

1. Open a Confluence page containing an embedded attachment.
2. Click the attachment to open it in Media Viewer.
3. Observe the filename displayed in the Media Viewer header.
4. Download the attachment using the Media Viewer download option.

Expected Results

• Media Viewer displays the correct attachment filename.
• Downloaded file retains the original attachment filename.

Actual Results

• Media Viewer displays the filename as "unknown".
• Downloaded file is saved as "original".
• Attachment preview loads successfully.

Workaround

Users can download affected files from the page's Attachments screen, where the original filename is preserved.

https://<site>.atlassian.net/wiki/pages/viewpageattachments.action?pageId=<pageID>

There is currently no known workaround for restoring the correct filename within Media Viewer. A workaround will be added here when available.