I added ionic to an existing angular application and ran into the following troubles after adding the ionic core css:
Error: Failed to find ‘@ionic/angular/css/core.css
Solution
When importing the css do this:
@import '@ionic/core/css/core.css';
instead of
@import '~@ionic/core/css/core.css';
Postcss cannot handle this tilde, but will interpret it correctly without!
A possible other solution could be that your IonicModule is not imported well. Add this to your app.module.ts imports []:
IonicModule.forRoot({
animated: false,
}),