Error message for pandoc-export org-export-barf-if-invalid-backend: Unknown "nil" backend: Aborting export

Since several years I prefer to generate documents from plain text which I then export to other formats. An crucial part is exporting to formats like PDF, Word or PowerPoint to share with others.

Pandoc provides all this and is an awesome tool. The last years the format was Markdown in Dendron in Visual Studio Code where I used the vscode-pandoc plugin to convert markdown documents to Word or PDF.

I have picked up Emacs again and Org mode. In the past the ox-pandoc exporter worked well. Today I had the need to convert some text for the first time since my switch back to Emacs.

Much to my surprise I noticed that the menu entries in the exporter menu had disappeared and calling the export directly led to the error message org-export-barf-if-invalid-backend: Unknown "nil" backend: Aborting export.

Initially I thought Emacs might not find the pandoc binary but it did. Also I couldn’t find any errors or omissions in the configuration.

Searching the web for this error led to this comment from 2021 in the org-reveal GitHub issues. It suggested that this happens if you customize org-export-backends. Indeed I had this in my configuration but I don’t know why. Once I removed it the export worked again.

I had neither time nor do I have the lisp skills to debug this but I’m glad the export works again!

Maybe this helps someone in the future who encounters the same issue.

It also serves as a reminder to not copy configuration without a specific need and to properly document each setting why it’s there.