Webpacker configuration file not found – Rails 6.0.0

Since Rails 6, Webpacker is the default JavaScript compiler. So you’ll also have to set it up before starting your Rails server.

1. Install yarn using your OS package manager, or take a look at https://yarnpkg.com/en/docs/install
2. Set it up rails webpacker:install
3. Make sure all packages are up to date yarn install --check-files
4. Start your Rails server rails s

Enjoy!