java.lang.NullPointerException at org.dartlang.vm.service.element.Element.jsonArrayToListString(Element.java:64)

Thanks for the feedback! If your issue is related to the Flutter framework itself, please open an issue at github.com/flutter/flutter.

Steps to Reproduce

Launched my application in the Android simulator. This error started showing up after added some new code to test out isolates / background jobs. See the // new tags in the code below.

---

import ‘package:flutter/material.dart’; import ‘default_route.dart’; import ‘TimeChart.dart’; import “dart:io”; import ‘package:flutter/foundation.dart’; import ‘dart:async’;

//add import to rendering library (for debugPaintSizeEnabled) import ‘package:flutter/rendering.dart’;

void main() async{ //debugPaintSizeEnabled=true; compute(_backgroundJob,0); // new runApp(App()); }

class App extends StatelessWidget { @override Widget build(BuildContext context) { print(“in App:build”); return MaterialApp( debugShowCheckedModeBanner: true, title: ‘My Application’, theme: ThemeData( primaryColor: Colors.blue, dialogBackgroundColor: Colors.blue, ), home: DefaultRoute(), ); } }

// new Future<String> _backgroundJob(int dummy) async { print(“starting backgroundJob”); while (true) { print(“in backgroundJob”); sleep(Duration(seconds: 10)); } return “done”; }

Version info

Please paste the output of running flutter doctor -v here (available from the command line or from Tools > Flutter > Flutter Doctor). It will provide the version of the Flutter framework as well as of the IntelliJ plugin.

Android Studio 3.1.4 • Flutter plugin io.flutter 28.0.1 • Dart plugin 173.4700

flutter doctor -v [√] Flutter (Channel beta, v0.7.3, on Microsoft Windows [Version 10.0.17134.285], locale en-US) • Flutter version 0.7.3 at C:\Users\rtola\dev\flutter • Framework revision 3b309bda07 (2 weeks ago), 2018-08-28 12:39:24 -0700 • Engine revision af42b6dc95 • Dart version 2.1.0-dev.1.0.flutter-ccb16f7282

[√] Android toolchain - develop for Android devices (Android SDK 28.0.1) • Android SDK at C:\Users\rtola\AppData\Local\Android\sdk • Android NDK location not configured (optional; useful for native profiling support) • Platform android-28, build-tools 28.0.1 • Java binary at: C:\Program Files\Android\Android Studio\jre\bin\java • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b02) • All Android licenses accepted.

[√] Android Studio (version 3.1) • Android Studio at C:\Program Files\Android\Android Studio • Flutter plugin version 28.0.1 • Dart plugin version 173.4700 • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b02)

[√] Connected devices (1 available) • Android SDK built for x86 • emulator-5554 • android-x86 • Android 9 (API 28) (emulator)

• No issues found!

Exception

null

java.lang.NullPointerException
	at org.dartlang.vm.service.element.Element.jsonArrayToListString(Element.java:64)
	at org.dartlang.vm.service.element.Element.getListString(Element.java:38)
	at org.dartlang.vm.service.element.Isolate.getExtensionRPCs(Isolate.java:67)
	at io.flutter.perf.PerfService$2$1.lambda$received$0(PerfService.java:85)
	at com.intellij.openapi.application.TransactionGuardImpl$2.run(TransactionGuardImpl.java:315)
	at com.intellij.openapi.application.impl.LaterInvocator$FlushQueue.runNextEvent(LaterInvocator.java:424)
	at com.intellij.openapi.application.impl.LaterInvocator$FlushQueue.run(LaterInvocator.java:407)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:762)
	at java.awt.EventQueue.access$500(EventQueue.java:98)
	at java.awt.EventQueue$3.run(EventQueue.java:715)
	at java.awt.EventQueue$3.run(EventQueue.java:709)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:732)
	at com.intellij.ide.IdeEventQueue.defaultDispatchEvent(IdeEventQueue.java:822)
	at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:650)
	at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:366)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

[devoncarew]

I’m surprised it doesn’t have that member, but we likely should throw here. We can move this to the protocol library repo.

[ghost]

This issue was moved by devoncarew to dart-lang/vm_service_drivers#185.