title: Flutter Web - Can't navigate through browser back and forward buttons
body: <p>In flutter web, I cant navigate through the back and forward buttons of the browser. It gives the following error:</p>
  <pre><code>Error: Assertion failed: org-dartlang-sdk:///flutter_web_sdk/lib/_engine/engine/navigation/history.dart:284:14
  _userProvidedRouteName != null
  is not true
      at Object.throw_ [as throw] (http://localhost:54382/dart_sdk.js:5344:11)
      at Object.assertFailed (http://localhost:54382/dart_sdk.js:5280:15)
      at _engine.SingleEntryBrowserHistory.new.onPopState (http://localhost:54382/dart_sdk.js:149735:59)
  Error: Assertion failed: org-dartlang-sdk:///flutter_web_sdk/lib/_engine/engine/navigation/history.dart:284:14
  _userProvidedRouteName != null
  is not true
      at Object.throw_ [as throw] (http://localhost:54382/dart_sdk.js:5344:11)
      at Object.assertFailed (http://localhost:54382/dart_sdk.js:5280:15)
      at _engine.SingleEntryBrowserHistory.new.onPopState (http://localhost:54382/dart_sdk.js:149735:59)
  </code></pre>