App stops on the push init action

[franzisk]

When I try to init the Push my app stops and the problem is on the init line:

const options: PushOptions = {
  android: {
    senderID: FCM_CONFIG.SENDER_ID
  },
  ios: {
    alert: 'true',
    badge: false,
    sound: 'true'
  },
  windows: {}
};
const pushObject: PushObject = this.push.init(options); // app stops here

Just to test, if I remove that line app starts normal, with that line it stops.

I followed this link to set the push: Push Notifications in Ionic

My config.xml:

<plugin name="phonegap-plugin-push" spec="~1.9.0">
    <variable name="SENDER_ID" value="MY_SENDER_ID_NUMBER" />
</plugin>