Error UserFriendly

There is a little static error builder hidden in the documentation.

When an error occurs while building a widget, the broken widget is replaced by the widget returned by this function. By default, an ErrorWidget is returned.

You can define in the the builder method of the MaterialApp widget.

 Widget buildError(BuildContext context, FlutterErrorDetails error) {
   return Scaffold(
     body: Center(
       child: Text(
         "Error appeared.",
         style: Theme.of(context).textTheme.title,
       ),
     )
   );
 }

 class MyApp extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
       theme: ThemeData(
         primarySwatch: Colors.blue,
       ),
       builder: (BuildContext context, Widget widget) {
         ErrorWidget.builder = (FlutterErrorDetails errorDetails) {
           return buildError(context, errorDetails);
         };

         return widget;
       },
       title: 'Flutter Demo',
       home: MyHomePage(title: 'Flutter Demo Home Page'),
     );
   }
 }