title: Ionic 4 Rest api calls not working on the Device with and without proxy. Getting Unknown error
body: <p>Ionic 4 app not working on device all API calls are saying unknown error
  working perfectly on ionic serve</p>
  <p>Tried</p>
  <ol>
  <li>Updated the <code>config.xml</code> with allowed and access tags</li>
  <li>updated API to allow access from same origin</li>
  <li>Updated the cordova plugins nothing
  seems working 4, Added to index file</li>
  </ol>
  <p>Config.xml</p>
  <pre><code>&lt;preference name=&quot;CordovaWebViewEngine&quot; value=&quot;CDVWKWebViewEngine&quot; /&gt;
   &lt;access origin=&quot;*&quot; /&gt;
     &lt;allow-intent href=&quot;http://*/*&quot; /&gt;
      &lt;allow-intent href=&quot;https://*/*&quot; /
  </code></pre>
  <p>index.html</p>
  <pre><code>&lt;meta http-equiv=&quot;Content-Security-Policy&quot; content=&quot;img-src 'self' data:; default-src *; style-src 'self' 'unsafe-inline'; script-src 'self' 'unsafe-inline' 'unsafe-eval'&quot;&gt;
  </code></pre>
  <p>Nothing seems working<br />
  <a href="https://i.stack.imgur.com/kQGm5.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/kQGm5.png" alt="" /></a></p>
  <pre><code>Cordova:
  
     cordova (Cordova CLI) : 8.1.2 (cordova-lib@8.1.1)
     Cordova Platforms     : android 7.1.4
     Cordova Plugins       : cordova-plugin-ionic-keyboard 2.1.3, cordova-plugin-ionic-webview 3.0.0, (and 7 other plugins)
  
  System:
  
     NodeJS : v10.7.0 (C:\Program Files\nodejs\node.exe)
     npm    : 5.3.0
     OS     : Windows 10
  
  ionic (Ionic CLI)             : 4.6.0
     Ionic Framework               : @ionic/angular 4.0.0-beta.7
     @angular-devkit/build-angular : 0.7.5
     @angular-devkit/schematics    : 0.7.5
     @angular/cli                  : 6.1.5
     @ionic/angular-toolkit        : not installed
  </code></pre>