Issue Summary

The cloud editor does not natively support cross-page attachments, leading to rendering failures for legacy content migrated from DC or created in the legacy editor. When the source page of an attachment is restricted, deleted, or renamed, the cloud editor can't resolve the reference, resulting in one of these errors:

• We couldn't load the file
• Preview unavailable
• Something went wrong. We couldn’t generate a preview for this file
• UNKNOWN_ATTACHMENT
• 403 Forbidden errors

Steps to Reproduce

1. Create a page using the legacy editor in DC.
2. Link an attachment from a different page or space to this page.
3. Migrate the content to Confluence Cloud (and convert the page to the cloud editor).
4. View the page as a user who does not have permissions to the source page where the attachment is hosted, or delete/rename the source page/attachment.

Expected Results

• The editor should be able to resolve cross-page attachment references or provide clear visibility into why an attachment can't be rendered (e.g., indicating a permission restriction or a broken link).

Actual Results

The attachment fails to render with one of the errors:

• We couldn't load the file
• Preview unavailable
• Something went wrong. We couldn’t generate a preview for this file
• UNKNOWN_ATTACHMENT
• 403 Forbidden errors

Workaround

• Users can examine the page's storage format to identify the origin space/page of the broken attachment and check permissions or past versions.
• Re-uploading images to the current page should fix the problem.
• Creating a copy of the page should also resolve the issue.