Under most circumstances, migrating between versions should be done by following these commands

    rm -rf node_modules
    npm run init
    

Specific version migrating

For major versions, outlined below are the steps and precautions when updating versions

Updating from 8.x to 9.x

This update modified the file name the JS file for development.
You'll need to change the name of the js file in /src/index.html from 'bundle.js' to 'index.js'