Can't `npm start` after addition of css modules to project

[wajd]

when attempting npm start after adding app.css in the Demo:css modules section of tutorial, this is returned: TypeError: Cannot read property 'filter' of undefined at findLoader (/Users/wjt/ReactProjects/welp/webpack.config.js:41:25) at Object. (/Users/wjt/ReactProjects/welp/webpack.config.js:48:1) at Module._compile (module.js:652:30) at Object.Module._extensions..js (module.js:663:10) at Module.load (module.js:565:32) at tryModuleLoad (module.js:505:12) at Function.Module._load (module.js:497:3) at Module.require (module.js:596:17) at require (internal/module.js:11:18) at Object. (/Users/wjt/ReactProjects/welp/node_modules/hjs-webpack/bin/hjs-dev-server.js:17:12) at Module._compile (module.js:652:30) at Object.Module._extensions..js (module.js:663:10) at Module.load (module.js:565:32) at tryModuleLoad (module.js:505:12) at Function.Module._load (module.js:497:3) at Function.Module.runMain (module.js:693:10) Failed to load webpack config, please use like this hjs-dev-server.js webpack.config.js

npm ERR! code ELIFECYCLE npm ERR! errno 1 npm ERR! welp@1.0.0 start: NODE_ENV=development ./node_modules/.bin/hjs-dev-server npm ERR! Exit status 1 npm ERR! npm ERR! Failed at the welp@1.0.0 start script. npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in: npm ERR! /Users/wjt/.npm/_logs/2018-06-29T07_44_31_216Z-debug.log

current suggested solution in comments is deleting node_modules directory, replacing webpack config file w/ tutorial repo version and reinstalling dependencies, theorising that a change in technologies is the reason for the failure, but I would rather find out how to do this using the updated technologies.

[jimmyFlash]

I'm getting the same error because : config.module.loaders is always returning undefined from webpack.config.js

[Lelouch-666]

Any solution?