# Content loader returned an entry with an invalid id.

> **Example error message:**\
> The content loader for the collection **blog** returned an entry with an invalid `id`:\
> {\
> “id”: 1,\
> “title”: “Hello, World!”\
> }

## What went wrong?

[Section titled “What went wrong?”](#what-went-wrong)

A content loader returned an invalid `id`. Make sure that the `id` of the entry is a string. See the [Content collections documentation](/en/guides/content-collections/) for more information.