Summary

With some PDF file (tested with signed PDF file), the rendering is incorrect. The PDF file may appear to be missing several contents (if not all) in the preview page from the attachment field. However, if the file is downloaded and viewed outside Confluence, it will appear normally.

Steps to Replicate the Issue

1. Create a new page in Confluence
2. Attach the signed PDF file.
3. Try to preview the file in Confluence.

Expected Results

The PDF is displayed normally in Thumbnail and Preview.

Actual Results

The PDF is displayed correctly Thumbnail but with missing contents in Preview

Workaround

Download the PDF file to be able to preview the file.