For some reason, installing plugins in Visual Studio Code doesn’t always pull stuff from NPM correctly.
If you get this error:
Cannot find module 'eslint-plugin-react'
This means you need to install this plugin into the global NPM registry:
npm install eslint-plugin-react -g
eslint-plugin-react@4.3.0 C:\Users\gary\AppData\Roaming\npm\node_modules\eslint-plugin-react