In my case, I was getting the error because I upgraded from Laravel Mix Version 2 to 5.
In Laravel Mix Version 2, you import vue components as follows:
Vue.component( 'example-component', require('./components/ExampleComponent.vue') );
In Laravel Mix Version 5, you have to import your components as follows:
import ExampleComponent from './components/ExampleComponent.vue'; Vue.component('example-component', ExampleComponent);
Here is the documentation: https://laravel-mix.com/docs/5.0/upgrade
Better, to improve performance of your app, you can lazy load your components as follows:
Vue.component("ExampleComponent", () => import("./components/ExampleComponent"));