title: Error implementing child routes in Angular 6
body: <p>I'm getting below error while implementing child routes for my project. I didn't find any help on GitHub and other sites.</p>
  
  <blockquote>
    <p>ERROR Error: Uncaught (in promise): SecurityError: Failed to execute
    'pushState' on 'History': A history state object with URL
    '<a href="http://%28routes%29/" rel="nofollow noreferrer">http://%28routes%29/</a>' cannot be created in a document with origin
    '<a href="http://localhost:4200" rel="nofollow noreferrer">http://localhost:4200</a>' and URL '<a href="http://localhost:4200/" rel="nofollow noreferrer">http://localhost:4200/</a>'. Error:
    Failed to execute 'pushState' on 'History': A history state object
    with URL '<a href="http://%28routes%29/" rel="nofollow noreferrer">http://%28routes%29/</a>' cannot be created in a document with
    origin '<a href="http://localhost:4200" rel="nofollow noreferrer">http://localhost:4200</a>' and URL '<a href="http://localhost:4200/" rel="nofollow noreferrer">http://localhost:4200/</a>'.</p>
  </blockquote>