Docusaurus error during building the project - docusaurus

Question

First of all let me say that I'm new of Docusaurus and I'm using version 2.
I was building my documentation project and I have got the following error:
Docusaurus Node/SSR could not render static page with path=/docs/My_MDX_Page because of error: useBaseUrl is not defined
I'm using a MDX page to get the baseURL to retrieve static contents.
The MDX page:
---
title: title
hide_title: true
sidebar_label: item
---
import useBaseUrl from '#docusaurus/useBaseUrl';
## Section
| Name | image |
| :--- | :--- |
| YL_GN3 | <img src={useBaseUrl('img/YL_GN3.png')} /> |
I think I'm doing something wrong even if executing without building it works (by npm start).

Answer 1

npm install was executed.
Here is the directory structure of project:
+ .docusaurus
+ build
+ docs
+ node_modules
+ src
+ static
+ versioned_docs
+ versioned_sidebars
babel.config.js
docusaurus.config.js
package-lock.json
package.json
README.md
sidebars.js
versions.json
UPDATE
For reasons that I don't know, it has started working. I have changed docusaurs config, adding the baseUrl different from '/' and 'index.js' in order to have the docs as landing page