App Works in Browser but not on iOS (presumption CORS problem)

Ionic Framework ionic-v3
1

Hi,

i switched my old app to WKWebView and got i white screen.

So i made a new simple app to test the new WKWebView.

When i run the app in a browser, all is fine, the json schema gets loaded.
If i run the app from my iphone, nothing happens…

On the server i send the header: **Access-Control-Allow-Origin: ***

The home.ts file:

import { Component, OnInit } from '@angular/core';
import { NavController } from 'ionic-angular';

import $RefParser from 'json-schema-ref-parser';

@Component({
  selector: 'page-home',
  templateUrl: 'home.html'
})
export class HomePage implements OnInit {
  public schema: Object;

  constructor(public navCtrl: NavController) {}

  public getFlatSchema(uri: string): Promise<Object> {
    let parser = new $RefParser();
    return parser.dereference(uri);
  }

  ngOnInit() {
    this.getFlatSchema("https://v22017084844652188.powersrv.de/schemas/test.json")
      .then((value) => {
        console.log("Schema fetched...");
        this.schema = value;
      })
      .catch(error => {
        console.log("Schema not fetched...");
        console.log(error);
      });
  }
}

I’m getting the following error:

Schema not fetched...
2017-11-04 17:45:13.077679+0100 MyApp[1910:333737] {"line":33786,"column":29,"sourceURL":"http://localhost:8080/var/containers/Bundle/Application/5F2507A6-B675-4269-95FC-398B8E58AE54/MyApp.app/www/build/vendor.js","__zone_symbol__currentTask":{"type":"microTask","state":"notScheduled","source":"Promise.then","zone":"angular","cancelFn":null,"runCount":0},"name":"Error","message":"Error downloading https://v22017084844652188.powersrv.de/schemas/test.json \nType error","stack":"http://localhost:8080/var/containers/Bundle/Application/5F2507A6-B675-4269-95FC-398B8E58AE54/MyApp.app/www/build/vendor.js:128504:19\nonInvoke@http://localhost:8080/var/containers/Bundle/Application/5F2507A6-B675-4269-95FC-398B8E58AE54/MyApp.app/www/build/vendor.js:4247:39\nrun@http://localhost:8080/var/containers/Bundle/Application/5F2507A6-B675-4269-95FC-398B8E58AE54/MyApp.app/www/build/polyfills.js:3:9529\nhttp://localhost:8080/var/containers/Bundle/Application/5F2507A6-B675-4269-95FC-398B8E58AE54/MyApp.app/www/build/polyfills.js:3:19625\nonInvokeTask@http://localhost:8080/var/containers/Bundle/Application/5F2507A6-B675-4269-95FC-398B8E58AE54/MyApp.app/www/build/vendor.js:4238:43\nrunTask@http://localhost:8080/var/containers/Bundle/Application/5F2507A6-B675-4269-95FC-398B8E58AE54/MyApp.app/www/build/polyfills.js:3:10224\no@http://localhost:8080/var/containers/Bundle/Application/5F2507A6-B675-4269-95FC-398B8E58AE54/MyApp.app/www/build/polyfills.js:3:7281\npromiseReactionJob@[native code]"}

I made a simple test app. You can access the repository here.

So, what do I wrong?