The webpage at package id://domain name/cordova/package id/callback?code=yROiScGzzRBUgyif&state=LjEkbMzq7Ja_P55vOT7Ux6xC9zN9Ne2Tj3P3KHTwmLM might be temporarily down or it may have moved permanently to a new web address.
ERR_UNKNOWN_URL_SCHEME
The error in question seems to indicate that the application was not properly configured in order to ensure that the custom scheme, like com.example, was registered as being handled by the application.
You need to ensure that the custom scheme you use is associated with the application. In addition, you should test the application through an emulator or on a real device as testing it in a browser will mean there’s no handler for the custom scheme which would result in errors similar to the ones you described.
A good way to be sure you did not miss any step would be to follow every step of the Ionic2 quickstart: https://auth0.com/docs/quickstart/native/ionic2