v4.0.1

Webpack5 removed automated polyfilling for node core modules. That means you might have to import them manually and alias them if you use packages that were not designed for browsers.

https://webpack.js.org/blog/2020-10-10-webpack-5-release/#automatic-nodejs-polyfills-removed

Though there is a plugin that do that for you, this is what this release adds.
https://npmjs.com/package/node-polyfill-webpack-plugin