Laravel Mix: These dependencies were not found:

I have a fresh install of Laravel 5.4. I as well have the folowing versions installed on my Windows PC node: 6.11.0 npm:5.0.3

I have already run npm install, however, when i run npm run watch, i get the following error

> @ watch C:\xampp\htdocs\tu
> cross-env NODE_ENV=development node_modules/webpack/bin/webpack.js --watch --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js

 10% building modules 1/1 modules 0 active
Webpack is watching the files…
                                                                                                                                95% emitting

 ERROR  Failed to compile with 2 errors                                                                                                                             12:12:42 AM

These dependencies were not found:

* C:\xampp\htdocs\tu\resources\assets\js\app.js in multi ./resources/assets/js/app.js ./resources/assets/sass/app.scss
* C:\xampp\htdocs\tu\resources\assets\sass\app.scss in multi ./resources/assets/js/app.js ./resources/assets/sass/app.scss

To install them, you can run: npm install --save C:\xampp\htdocs\tu\resources\assets\js\app.js C:\xampp\htdocs\tu\resources\assets\sass\app.scss

I've searched the internet but cant seem to get it working. Any help is appreciated.