> For the complete documentation index, see [llms.txt](https://docs.imerit.net/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.imerit.net/troubleshooting/i-get-a-unknown-classification-warning-when-opening-a-task.md).

# I get a "Unknown Classification" warning when opening a task

<figure><img src="/files/xikWcZt6UknuOo2K97o5" alt="" width="375"><figcaption></figcaption></figure>

This means that this classification was removed from the project's category schema after it was answered in the task.

From your project's *Settings -> Category Schema* section, by clicking on the "Show/Hide Version History" button, you may browse previous versions of your project's category schema to attempt to restore it.

<figure><img src="/files/L1Yj3pgdLTgkfOREGWR4" alt="" width="375"><figcaption></figcaption></figure>