Impossible to play video in flutter - flutter

Question

I try to play video in flutter, and when i launch my code i have this problem
Unhandled Exception: PlatformException(channel-error, Unable to establish connection on channel., null, null)
This my code:
I create a class VideoApp extend statefulwidget.
_controller contain the video
import 'package:video_player/video_player.dart';
import 'package:flutter/material.dart';
void main() => runApp(VideoApp());
class VideoApp extends StatefulWidget {
#override
_VideoAppState createState() => _VideoAppState();
}
class _VideoAppState extends State<VideoApp> {
VideoPlayerController _controller;
#override
void initState() {
super.initState();
_controller = VideoPlayerController.network(
'http://www.sample-videos.com/video123/mp4/720/big_buck_bunny_720p_20mb.mp4')
..initialize().then((_) {
// Ensure the first frame is shown after the video is initialized, even before the play button has been pressed.
setState(() {});
});
}
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Video Demo',
home: Scaffold(
body: Center(
child: _controller.value.initialized
? AspectRatio(
aspectRatio: _controller.value.aspectRatio,
child: VideoPlayer(_controller),
)
: Container(),
),
floatingActionButton: FloatingActionButton(
onPressed: () {
setState(() {
_controller.value.isPlaying
? _controller.pause()
: _controller.play();
});
},
child: Icon(
_controller.value.isPlaying ? Icons.pause : Icons.play_arrow,
),
),
),
);
}
#override
void dispose() {
super.dispose();
_controller.dispose();
}
}