First page goes blank in PDF when Signature Fields are added on the last page

Description: I have identified a specific rendering bug in ONLYOFFICE Desktop Editors (v9.3.1.8) on Fedora Linux. When a document contains interactive Form Fields (from the Forms tab) combined with an Image (scan of a signature) on the final page, the first page of the exported PDF becomes invisible (renders as blank white).

Steps to Reproduce:

  1. Create a multi-page pdf-document (e.g., 9+ pages).

  2. Go to the last page and insert two Signature Fields using the Forms tab and attach image to these fields.

  3. Save the document.

  4. Open the PDF in any viewer (Okular, OnlyOffice, etc.).

Expected Result: The entire document, including the first page, should be visible.

Actual Result: The first page is rendered as a solid white block. The text is technically there (searchable/selectable), but visually hidden. Standard PDF recovery tools (Ghostscript, mutool) cannot restore visibility, confirming a structural corruption during export.

Key Observations:

  • Trigger: The bug is specifically tied to the Signature Fields from the Forms tab.

  • Resolution: Removing these Form Fields immediately fixes the problem; the first page becomes visible again.

  • Layout: There are no images on the first page (text only). The only image in the document is the signature scan on the final page.

  • Environment: Occurs on Fedora Linux with OnlyOffice Desktop Editors v9.3.1.8. Hardware acceleration settings do not affect the outcome.

I can send you the document containing this bug, but I don’t want to publish this document publicly.

Hello, @Golembivskyi !

Could you please record a short video showing the whole reproduction process step by step and send it to me via private message on the forum, together with the affected document, if you prefer not to publish them here? If the video file is too large to attach in a private message, please upload it to any cloud storage and send me the link there.

Once I receive the video and the file, I will continue checking the issue.