How to Fix Pandoc Word Export Errors: Solving YAML Metadata Issues

Introduction: A Developer’s Headache

Have you ever experienced this scenario? You’ve written a Markdown file flawlessly, exporting it to PDF via Pandoc works perfectly, but when you try to export it to Word, you get this cryptic error:

Error parsing YAML metadata at "./Lynx_Towards_High-Fidelity_Personalized_Video_Generation.md" (line 1, column 1): 
YAML parse exception at line 1, column 11: mapping values are not allowed in this context

You check the first line, everything seems fine, colons have spaces, yet the error persists. You might try deleting the Word template, reinstalling Pandoc, or rewriting the Markdown—but nothing works. This “metadata error with confusing messages” is a common headache for developers writing academic papers or technical documentation.

This guide will walk you through the root cause and step-by-step solutions so that YAML metadata errors in Pandoc Word exports become easy to handle.

1. Understanding the Error: What Does This YAML Metadata Error Mean?

Pandoc allows you to define YAML metadata blocks at the top of Markdown files to specify the title, author, date, keywords, and more:

---
title: "Lynx: Towards High-Fidelity Personalized Video Generation"
author: "Author Name"
date: "2025-09-28"
keywords: ["video generation", "AI", "deep learning"]
---

The core issue: Pandoc fails to parse YAML when it encounters syntax that does not conform to YAML standards.

  • line 1, column 11: points to the problematic character in the first line.
  • mapping values are not allowed in this context: indicates a key: value mapping was found but could not be parsed—commonly caused by colon misuse or formatting errors.

Pandoc’s YAML parser is strict: even minor formatting mistakes can trigger errors.

2. Common YAML Metadata Issues and Fixes

2.1 Missing --- at the Start or End

Incorrect Example:

title: "Lynx: Towards High-Fidelity Personalized Video Generation"
author: "Author Name"

Fix: Wrap the YAML block with ---:

---
title: "Lynx: Towards High-Fidelity Personalized Video Generation"
author: "Author Name"
---

2.2 Missing Space After Colon

Incorrect Example:

title:"Lynx"

Issue: YAML requires a space after the colon.

Correct Example:

title: "Lynx"

2.3 Colons or Special Characters in Values Without Quotes

Incorrect Example:

title: Lynx: Towards High-Fidelity Personalized Video Generation

Issue: The colon in the value is interpreted as a new key.

Correct Example:

title: "Lynx: Towards High-Fidelity Personalized Video Generation"

Tip: Wrap strings containing :, #, %, & in double quotes.

2.4 List or Indentation Errors

Incorrect Example:

authors:
- name: Author Name
 - affiliation: AI Lab

Fix: Use consistent spaces (no tabs) and align list keys:

authors:
  - name: "Author Name"
    affiliation: "AI Lab"

2.5 File Encoding or Invisible Characters

  • YAML is sensitive to BOM (Byte Order Mark); UTF-8 files with BOM may fail.
  • Hidden spaces or full-width characters can trigger parsing errors.

Check Encoding (macOS/Linux):

file -I ./Lynx_Towards_High-Fidelity_Personalized_Video_Generation.md
xxd ./Lynx_Towards_High-Fidelity_Personalized_Video_Generation.md | head

Remove BOM or invalid characters:

iconv -f UTF-8 -t UTF-8 -c ./Lynx_Towards_High-Fidelity_Personalized_Video_Generation.md -o ./Lynx_Clean.md

3. Step-by-Step Debugging Workflow

  1. Confirm the Markdown file starts with a --- wrapped YAML block.
  2. Ensure every key: value line has a space after the colon.
  3. Wrap values with colons or special characters in quotes.
  4. Check list indentation—only spaces, no tabs.
  5. Verify file encoding: UTF-8 without BOM.
  6. Temporarily remove the YAML block to see if the error disappears.
  7. Validate YAML using online lint tools or yamllint.

4. Correct YAML Example for Markdown

---
title: "Lynx: Towards High-Fidelity Personalized Video Generation"
author: "Author Name"
date: "2025-09-28"
keywords: ["video generation", "AI", "deep learning"]
authors:
  - name: "Author Name"
    affiliation: "AI Lab"
---

Export to Word:

pandoc ./Lynx_Towards_High-Fidelity_Personalized_Video_Generation.md -o output.docx

With a custom Word template:

pandoc ./Lynx_Towards_High-Fidelity_Personalized_Video_Generation.md \
       --lua-filter=table-style.lua \
       --reference-doc=reference_sample.docx \
       -o output.docx

5. Advanced Tips and Best Practices

  • Multiple authors or affiliations: Use list structures with consistent indentation.
  • Special characters: Markdown symbols like _ or * don’t affect YAML, but always quote values in YAML.
  • Automation: Integrate yamllint or pre-commit hooks in CI/CD pipelines to prevent errors.
  • Pandoc versions: Use the latest stable release, as older versions have stricter YAML parsing.

6. Frequently Asked Questions (FAQ)

Q1: Can I skip YAML and put metadata in the body?
A: Yes, but Word export won’t automatically apply template styles like title or author.

Q2: No YAML block, still getting errors—what now?
A: Some templates or Lua filters require metadata. Adding an empty block ---\n--- can resolve it.

Q3: How do I specify metadata via command line instead of writing YAML?
A: Use -M or --metadata:

pandoc input.md -o output.docx -M title="Lynx"

Q4: How do I make long YAML readable?
A: Use indentation, line breaks, lists, and quote special characters. For multi-line values, consider literal blocks | or folded blocks >.

7. Summary and Actionable Takeaways

  1. YAML syntax matters: space after colons, quote special characters, consistent indentation.
  2. File encoding: UTF-8 without BOM.
  3. Validation tools: yamllint or online YAML validators.
  4. Isolate errors: temporarily remove YAML block for debugging.
  5. Template awareness: ensure key metadata fields exist when using Word templates.