Issue Summary

PDF attachments migrated from Confluence Data Center to Confluence Cloud fail to render as thumbnails/cards, appearing only as simple text links.

Steps to Reproduce

• On Confluence Data Center (Source): Create a page and upload a PDF attachment using the "Thumbnail" or "View File" macro format. Source Storage Format: 

<p><ac:structured-macro ac:name="view-file" ac:schema-version="1" ac:macro-id="40156b4e-7c3a-4ed8-91c3-04f4ba287c60"><ac:parameter ac:name="name"><ri:attachment ri:filename="Test PDF file.pdf" /></ac:parameter><ac:parameter ac:name="height">250</ac:parameter></ac:structured-macro></p>

• Migration: Perform a Data Center to cloud migration (DC2C) using CCMA.
• On Confluence Cloud (Destination): View the migrated page and inspect the storage format. Cloud Storage Format (remains identical): 

<p><ac:structured-macro ac:name="view-file" ac:schema-version="1" ac:macro-id="40156b4e-7c3a-4ed8-91c3-04f4ba287c60"><ac:parameter ac:name="name"><ri:attachment ri:filename="Test PDF file.pdf" /></ac:parameter><ac:parameter ac:name="height">250</ac:parameter></ac:structured-macro></p>

• It shows as a link on the cloud side

Expected Results

PDF attachments should render as thumbnails or card previews (Smart Links) on Confluence Cloud, maintaining parity with the visual representation on the source Data Center instance.

Actual Results

Despite the storage format being preserved correctly during migration, Confluence Cloud renders the view-file macro as a simple text link rather than a thumbnail or card preview. This indicates a limitation in how the cloud editor/renderer processes the legacy view-file macro storage format for PDF attachments.

Workaround

There is currently no automated workaround. Users must manually edit each affected page and re-insert or convert the link to a thumbnail/card format within the Cloud editor.