Problems with mini-css-extract-plugin

[yannviroulaud]

After a first npm install I got some errors (like Npm login needed) or some fail on some packages.
Have to install them 1 by 1 (like optimist)

webpack 5.21.2
webpack-cli 4.5.0
webpack-dev-server 3.11.2

When i'm trying to npm start I got this message =>
[webpack-cli] Error: Cannot find module 'mini-css-extract-plugin'

Anyone can help me ?