title: Unhandled Exception: A ChangeNotifier was used after being disposed
body: <p>I'm getting this error message:</p>
  <pre><code>Unhandled Exception: A ModeManager was used after being disposed.
  </code></pre>
  <p>I'm using <strong>ChangeNotifier</strong> (class <strong>ModeManager</strong>) together with <strong>ChangeNotifierProvider</strong>.
  Build method, where I create Provider looks like this:</p>
  <pre><code>@override
  Widget build(BuildContext context) {
      return !_isLoaded ? Center(child: CircularProgressIndicator()) : ChangeNotifierProvider(
          create: (_) =&gt; ModeManager(_appUser),
          child: Scaffold(
              appBar: AppBar(
              title: Text('Connect Spotify'),
              ),
              body: AddSpotifyScreenBody(),
          ),
      );
  }
  </code></pre>
  <p>Widget where I use provider looks something like this:</p>
  <pre><code>class _AddSpotifyScreenBodyState extends State&lt;AddSpotifyScreenBody&gt; {
    @override
    Widget build(BuildContext context) {
      var provider = Provider.of&lt;ModeManager&gt;(context);
      return Center(
        child: Padding(
          padding: EdgeInsets.all(20.0),
          child: Column(
            children: &lt;Widget&gt;[
              Text(provider.isCollecting ? 'COLLECTING NOW' : 'SHARING NOW'),
              //...some other widgets using provider...
            ],
          ),
        ),
      );
    }
  }
  </code></pre>
  <p>Does anybody know what could cause this error or what am I doing wrong? Thank You very much.</p>