---
title: "Document Engine knowledge base"
canonical_url: "https://www.nutrient.io/guides/document-engine/kb/"
md_url: "https://www.nutrient.io/guides/document-engine/kb.md"
last_updated: "2026-05-14T21:57:26.840Z"
description: "Explore FAQs and troubleshooting tips for Document Engine. Find solutions for SSL certificate problems, document storage, PDF downloading issues, and more. Learn how to integrate Document Engine effectively."
---

# Knowledge base

Our knowledge base helps you troubleshoot common issues, understand key functionalities, and optimize your experience with our document processing solutions.

## SSL/TLS and network issues

- [‘Unknown CA’ and other SSL certificate issues when adding document from a URL](https://www.nutrient.io/guides/document-engine/knowledge-base/remote-url-certificates.md)

- [Unable to download PDF with NGINX as a reverse proxy](https://www.nutrient.io/guides/document-engine/knowledge-base/unable-to-download-pdf-with-nginx-reverse-proxy.md)

## Document Engine operation and monitoring

- [Monitoring Document Engine](https://www.nutrient.io/guides/document-engine/knowledge-base/monitoring.md)

- [How to convert an XLSM file to PDF using Document Engine](https://www.nutrient.io/guides/document-engine/knowledge-base/xlsm-to-pdf-conversion.md)

## Document storage and retrieval

- [Remote document storage](https://www.nutrient.io/guides/document-engine/knowledge-base/remote-document-storage.md)

- [hash_mismatch error](https://www.nutrient.io/guides/document-engine/knowledge-base/hash-mismatch-error.md)

## Signing service issues

- [Signing service not available](https://www.nutrient.io/guides/document-engine/knowledge-base/signing-service-not-available.md)
---

## Related pages

- [Demo: Document Engine](/guides/document-engine/demo.md)
- [Changelog for Document Engine](/guides/document-engine/changelog.md)
- [Download Document Engine](/guides/document-engine/downloads.md)
- [Example projects](/guides/document-engine/example-projects.md)
- [Document Engine PDF server](/guides/document-engine.md)
- [Developer guides](/guides/document-engine/intro.md)
- [Nightly build](/guides/document-engine/nightly.md)
- [PDF rendering server](/guides/document-engine/rendering.md)
- [Troubleshooting](/guides/document-engine/troubleshoot.md)