Webpacker error when running server for new Rails app

Just created a brand new Rails app and receiving this error when I run the server:

Webpacker can't find application.js in /public/packs/manifest.json. Possible causes:1. You want to set webpacker.yml value of compile to true for your environment   unless you are using the `webpack -w` or the webpack-dev-server.2. webpack has not yet re-run to reflect updates.3. You have misconfigured Webpacker's config/webpacker.yml file.4. Your webpack configuration is not creating a manifest.Your manifest contains:{}

Here's my webpacker.yml:

# Note: You must restart bin/webpack-dev-server for changes to take effectdefault: &default  source_path: app/javascript  source_entry_path: packs  public_output_path: packs  cache_path: tmp/cache/webpacker  webpack_compile_output: false  # Additional paths webpack should lookup modules  # ['app/assets', 'engine/foo/app/assets']  resolved_paths: []  # Reload manifest.json on all requests so we reload latest compiled packs  cache_manifest: false  extensions:    - .js    - .sass    - .scss    - .css    - .module.sass    - .module.scss    - .module.css    - .png    - .svg    - .gif    - .jpeg    - .jpgdevelopment:<<: *default  compile: true  # Reference: https://webpack.js.org/configuration/dev-server/  dev_server:    https: false    host: localhost    port: 3035    public: localhost:3035    hmr: false    # Inline should be set to true if using HMR    inline: true    overlay: true    compress: true    disable_host_check: true    use_local_ip: false    quiet: false    headers:'Access-Control-Allow-Origin': '*'    watch_options:      ignored: '**/node_modules/**'test:<<: *default  compile: true  # Compile test packs to a separate directory  public_output_path: packs-testproduction:<<: *default  # Production depends on precompilation of packs prior to booting for performance.  compile: false  # Cache manifest.json for performance  cache_manifest: true

After running ./bin/webpack, it recommended I install webpack-cli via yarn add -D.After I did this, I got the following error:

Error: Cannot find module 'webpack-cli'Require stack:- ../node_modules/webpack/bin/webpack.js    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:1030:15)    at Function.Module._load (internal/modules/cjs/loader.js:899:27)    at Module.require (internal/modules/cjs/loader.js:1090:19)    at require (internal/modules/cjs/helpers.js:75:18)    at ../node_modules/webpack/bin/webpack.js:143:5    at processTicksAndRejections (internal/process/task_queues.js:93:5) {  code: 'MODULE_NOT_FOUND',  requireStack: ['../node_modules/webpack/bin/webpack.js'  ]

I don't have a manifest.json - shouldn't this have been created automatically?

Any ideas?