On Flutter Parsing Json in The Background fails - json

Question

I try to implement the Parsing JSON in the background on https://flutter.io/cookbook/networking/background-parsing/ and I am getting bellow error. Error also same when I use the Android Emulator.
I am using macOs HighSierra. I install IntelliJ and Fluter and Dark plugin. I test most examples on Flutter and it all worked. I also created a demo up and its working. I don't understand why this not working. Any Help please?
Code I am using:
import 'dart:async';
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:http/http.dart' as http;
// JSON::WEATHER
Future<String> getWeatherData() async {
var response = await http.get(
Uri.encodeFull("http://api.openweathermap.org/data/2.5/forecast?q=San+Francisco&units=metric&APPID=14cc828bff4e71286219858975c3e89a"),
headers: {
'Accept': 'application/json'
}
);
this.setState(() {
weatherData = json.decode(response.body);
});
return 'Success!';
}
#override
void initState() {
// TODO: implement initState
super.initState();;
this.getWeatherData();
}
// USAGE
new Text(
weatherData['list'][0]['main']['temp_min'].toString(),
style: new TextStyle(
fontSize: 10.0,
fontWeight: FontWeight.w400,
color: Colors.white,
),
),
Launching lib/main.dart on SM G935F in debug mode...
Initializing gradle...
Resolving dependencies...
Running 'gradlew assembleDebug'...
Built build/app/outputs/apk/debug/app-debug.apk (31.4MB).
I/FlutterActivityDelegate(26125): onResume setting current activity to this
D/libGLESv2(26125): STS_GLApi : DTS is not allowed for Package : com.yourcompany.parsingjsonintheackground
Syncing files to device SM G935F...
F/flutter (26125): [FATAL:flutter/fml/message_loop.cc(23)] Check failed: loop != nullptr.
MessageLoop::EnsureInitializedForCurrentThread was not called on this
thread prior to message loop use.
F/libc (26125): Fatal signal 6 (SIGABRT), code -6 in tid 26165 (1.ui)
* *
Build fingerprint: 'samsung/hero2ltexx/hero2lte:7.0/NRD90M/G935FXXS2DRC3:user/release-keys'
Revision: '9'
ABI: 'arm64'
pid: 26125, tid: 26165, name: 1.ui >>> com.yourcompany.parsingjsonintheackground <<<
signal 6 (SIGABRT), code -6 (SI_TKILL), fault addr --------
Abort message: '[FATAL:flutter/fml/message_loop.cc(23)] Check failed: loop != nullptr.
MessageLoop::EnsureInitializedForCurrentThread was not called on this
thread prior to message loop use.
'
x0 0000000000000000 x1 0000000000006635 x2 0000000000000006 x3 0000000000000008
x4 000000000000015f x5 0000000000000000 x6 0000007286ce8000 x7 0000000000000000
x8 0000000000000083 x9 ffffffffffffffdf x10 0000000000000000 x11 ffffffffffffffff
x12 0000000000000018 x13 0000000000000000 x14 0000000000000000 x15 000bbc6bf4faa710
x16 00000072840caee0 x17 0000007284073a28 x18 000000726095d160 x19 000000725d9ab4f8
x20 0000000000000006 x21 000000725d9ab450 x22 0000000000000000 x23 000000725d9ab020
x24 000000725d9ab038 x25 000000725d9ab040 x26 000000725d9ab060 x27 000000725d9ab098
x28 000000725d9ab009 x29 000000725d9aab00 x30 0000007284070ebc
sp 000000725d9aaae0 pc 0000007284073a30 pstate 0000000060000000
backtrace:
#00 pc 000000000006ca30 /system/lib64/libc.so (tgkill+8)
#01 pc 0000000000069eb8 /system/lib64/libc.so (pthread_kill+64)
#02 pc 0000000000024198 /system/lib64/libc.so (raise+24)
#03 pc 000000000001c9b0 /system/lib64/libc.so (abort+52)
#04 pc 00000000003a6d2c /data/app/com.yourcompany.parsingjsonintheackground-1/lib/arm64/libflutter.so
#05 pc 00000000003a7474 /data/app/com.yourcompany.parsingjsonintheackground-1/lib/arm64/libflutter.so
#06 pc 000000000016dab4 /data/app/com.yourcompany.parsingjsonintheackground-1/lib/arm64/libflutter.so
#07 pc 000000000015f404 /data/app/com.yourcompany.parsingjsonintheackground-1/lib/arm64/libflutter.so
#08 pc 0000000000189b70 /data/app/com.yourcompany.parsingjsonintheackground-1/lib/arm64/libflutter.so
#09 pc 0000000000190b50 /data/app/com.yourcompany.parsingjsonintheackground-1/lib/arm64/libflutter.so
#10 pc 0000000000190674 /data/app/com.yourcompany.parsingjsonintheackground-1/lib/arm64/libflutter.so
#11 pc 00000000001921e8 /data/app/com.yourcompany.parsingjsonintheackground-1/lib/arm64/libflutter.so
#12 pc 00000000005dc220 /data/app/com.yourcompany.parsingjsonintheackground-1/lib/arm64/libflutter.so
#13 pc 0000000000830f4c /data/app/com.yourcompany.parsingjsonintheackground-1/lib/arm64/libflutter.so
#14 pc 0000000000830df8 /data/app/com.yourcompany.parsingjsonintheackground-1/lib/arm64/libflutter.so
#15 pc 000000000074d084 /data/app/com.yourcompany.parsingjsonintheackground-1/lib/arm64/libflutter.so
#16 pc 00000000000696bc /system/lib64/libc.so (_ZL15__pthread_startPv+196)
#17 pc 000000000001dbf0 /system/lib64/libc.so (__start_thread+16)
Lost connection to device.

Answer 1

I answered in the related bug you opened:
https://github.com/flutter/flutter/issues/16738