Flutter application throws Http Exception and instantly crashes

Question

currently I'm having a problem with running flutter applications. I tried to search solutions, but none of them was actually my case. The problem is, when I try to install an application, sometimes it starts running, but instantly crashes, or not even build, and throws this exception (even with flutter demo project):

Error connecting to the service protocol: HttpException: Connection closed before full header was received, uri = http://127.0.0.1:57564/ws".

What I've tried so far: Cleaning cashes, reinstall flutter/android studio. I got this problem only with a few (android os) mobile. import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: Scaffold(appBar: AppBar(title: Text("App"))),
    );
  }
}

I think you should post the whole code to let us understand where the error is! — Saltae, Mar 11 '19 at 09:03
I posted code, and as you can see, it's very-very simple. I don't use http anywhere, btw, this error happens every time, it doesn't matter what the code is — Patrick Visi, Mar 11 '19 at 09:20
I solved it by setting a mobile device and laptop on the same wifi network. Sometimes I need to restart the mobile device. — Amol Gangadhare, Mar 11 '19 at 09:42
I have the same problem, if you happen to solve this somehow please answer your own question. — Loolooii, Jun 01 '19 at 22:17

score 6 · Answer 1 · answered May 27 '19 at 16:57

6

I solved this problem creating a new emulator device but NOT using the most recent Android Image.

Android Studio > Configure > AVD Manager > Create Virtual Device > (Choose a device model) > (Select a system image, but NOT the most recent)

In my case, I had the following Android images as choices: Q, Pie 28, Oreo 27 and 26, etc. I selected Pie 28 and the problem was solved. The problem was occuring with Android Q (most recent).

answered May 27 '19 at 16:57

Marcelo Gouveia

69
1
2

1

I don't think this fixed it. I'm not on Android Q and I have this problem too and creating a new virtual device didn't fix it for me. – Loolooii Jun 01 '19 at 22:17
@Loolooii Did you try API version 28? Curious if that works for you. – dustinrwh Jun 14 '19 at 21:26
@dustinrwh This problem went away when I removed one of the plugins I was using. I just tried removing them one by one. Specifically it was `flutter_webview_plugin` causing this problem apparently. I'm not sure if your issue is also caused by something like this. – Loolooii Jun 16 '19 at 20:22

score 1 · Answer 2 · answered Jun 12 '19 at 04:57

1

The problem is with the API version. Choose 28 It fixes the problem.

answered Jun 12 '19 at 04:57

Shiva Pandey

645
6
17

score 1 · Answer 3 · edited Dec 05 '19 at 08:40

1

I use a real device and my problem was only solved when I deleted a plugin from pubspec.yaml file. Maybe this can help.

edited Dec 05 '19 at 08:40

zeroDivider

1,050
13
29

answered Dec 04 '19 at 21:01

Renan

11
1

Flutter application throws Http Exception and instantly crashes

3 Answers3