[Bug]: Signed document PDF sent by email is 0 bytes – file exists on server but /files/<pdf> returns 404

[vassiskansa]

Issue Description

When a document signing process is completed, the final signed PDF attached to the completion email arrives as a 0-byte file, while the certificate PDF is delivered correctly.

Inside the server container the signed PDF is actually generated and stored correctly on disk, but accessing it through the /files/.pdf endpoint returns 404 Not Found.

Additionally, the MongoDB _File collection appears to remain empty, suggesting that the generated file is written to the filesystem but not registered in Parse Server’s file storage.

This causes the email system to attach an empty file when sending the completed document.

Environment:

OpenSign deployed with Docker

MongoDB running in container

Reverse proxy (Caddy)

SMTP configured and working

Latest available OpenSign Docker image

The signing workflow itself works correctly and documents are marked as completed.

Expected Behavior

After all parties sign a document:

The signed PDF should be generated.

The file should be registered in the Parse _File collection.

The endpoint /files/.pdf should return HTTP 200.

The completion email should include the correct signed PDF as attachment.

Current Behavior

Current Behavior

The document signing workflow completes successfully.

The signed PDF file is created on disk inside the container.

Accessing /files/.pdf returns 404 Not Found.

MongoDB _File collection remains empty.

The completion email attaches a 0-byte PDF file instead of the signed document.

The certificate PDF attachment is generated and delivered correctly.

Steps to reproduce

Steps to Reproduce

Deploy OpenSign using Docker.

Configure SMTP for email notifications.

Upload a document template.

Send the document for signing.

Complete the signing process with all parties.

Wait for the completion email.

Observe that:

the certificate attachment is valid

the signed document attachment is 0 bytes

Verify the filesystem inside the server container:

the signed PDF exists on disk

Test file access through the OpenSign endpoint:

/files/.pdf returns 404

Inspect MongoDB:

_File collection is empty.

If additional logs or configuration details are needed, I would be happy to provide them.

Screenshots of the issue(optional)

No response

Operating System [e.g. MacOS Sonoma 14.1, Windows 11]

Ubuntu 24.04.4 LTS

What browsers are you seeing the problem on?

Chrome, Firefox

What version of OpenSign™ are you seeing this issue on? [e.g. 1.0.6]

2.37.0

What environment are you seeing the problem on?

Hosted (app.yourdomain.com)

Please check the boxes that apply to this issue report.

• I have searched the existing issues & discussions to make sure that this is not a duplicate.

Code of Conduct

• I agree to follow this project's Code of Conduct
• I have searched the existing issues & discussions to make sure that this is not a duplicate.