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bug: a few hot restarts cause a canvaskit failure #140684
Description
Steps to reproduce
- Open example in VSCode, chose web platform
- Set a breakpoint on line that calls runApp
- Debug
- Then the breakpoint is hit, click hot restart a few times
Issues related:
Expected results
Not error when make hot reload
Actual results
The app is freezed and show a error in console. The dialog of "Flutter: Hot reloading" not close.
Code sample
Code sample
import 'package:flutter/material.dart';
void main() => runApp(const MyApp());
class MyApp extends StatelessWidget {
const MyApp({super.key});
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Material App',
home: Scaffold(
appBar: AppBar(
title: const Text('Material App Bar'),
),
body: const Center(
child: Text('Hello World'),
),
),
);
}
}
Logs
Logs
Launching lib/main.dart on Chrome in debug mode...
This app is linked to the debug service: ws://127.0.0.1:64538/SH-yEsqGG2I=/ws
Debug service listening on ws://127.0.0.1:64538/SH-yEsqGG2I=/ws
Connecting to VM Service at ws://127.0.0.1:64538/SH-yEsqGG2I=/ws
Restarted application in 1,307ms.
Error: Expected a wrapped Dart object, but got a JS object or a wrapped Dart object from a separate runtime instead.
dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/errors.dart 294:3 throw_
dart-sdk/lib/_internal/js_shared/lib/js_interop_patch.dart 89:7 JSBoxedDartObjectToObject.get$35toDart
lib/_engine/engine/canvaskit/native_memory.dart 24:46 <fn>
dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/operations.dart 574:37 _checkAndCall
dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/operations.dart 579:39 dcallIn some case show this error to
Restarted application in 2,200ms.
Error: Expected a wrapped Dart object, but got a JS object or a wrapped Dart object from a separate runtime instead.
dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/errors.dart 294:3 throw_
dart-sdk/lib/_internal/js_shared/lib/js_interop_patch.dart 89:7 JSBoxedDartObjectToObject.get$35toDart
lib/_engine/engine/canvaskit/native_memory.dart 24:46 <fn>
dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/operations.dart 574:37 _checkAndCall
dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/operations.dart 579:39 dcallFlutter Doctor output
Doctor output
[✓] Flutter (Channel stable, 3.16.5, on macOS 14.2 23C64 darwin-arm64, locale es-US)
• Flutter version 3.16.5 on channel stable at /Users/yeikel/fvm/versions/3.16.5
• Upstream repository https://github.com/flutter/flutter.git
• Framework revision 78666c8dc5 (hace 8 días), 2023-12-19 16:14:14 -0800
• Engine revision 3f3e560236
• Dart version 3.2.3
• DevTools version 2.28.4
[✓] Android toolchain - develop for Android devices (Android SDK version 33.0.1)
• Android SDK at /Users/yeikel/Library/Android/sdk/
• Platform android-34, build-tools 33.0.1
• ANDROID_HOME = /Users/yeikel/Library/Android/sdk/
• Java binary at: /Applications/Android Studio 2.app/Contents/jbr/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 17.0.6+0-17.0.6b802.4-9586694)
• All Android licenses accepted.
[✓] Xcode - develop for iOS and macOS (Xcode 15.1)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Build 15C65
• CocoaPods version 1.14.3
[✓] Chrome - develop for the web
• Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome
[✓] Android Studio (version 2020.3)
• Android Studio at /Applications/Android Studio 2020.3.1.app/Contents
• Flutter plugin can be installed from:
🔨 https://plugins.jetbrains.com/plugin/9212-flutter
• Dart plugin can be installed from:
🔨 https://plugins.jetbrains.com/plugin/6351-dart
• Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7249189)
[✓] Android Studio (version 2021.3)
• Android Studio at /Applications/Android Studio.app/Contents
• Flutter plugin can be installed from:
🔨 https://plugins.jetbrains.com/plugin/9212-flutter
• Dart plugin can be installed from:
🔨 https://plugins.jetbrains.com/plugin/6351-dart
• Java version OpenJDK Runtime Environment (build 11.0.13+0-b1751.21-8125866)
[✓] Android Studio (version 2022.2)
• Android Studio at /Applications/Android Studio 2.app/Contents
• Flutter plugin can be installed from:
🔨 https://plugins.jetbrains.com/plugin/9212-flutter
• Dart plugin can be installed from:
🔨 https://plugins.jetbrains.com/plugin/6351-dart
• Java version OpenJDK Runtime Environment (build 17.0.6+0-17.0.6b802.4-9586694)
[✓] VS Code (version 1.84.2)
• VS Code at /Applications/Visual Studio Code.app/Contents
• Flutter extension version 3.78.0
[✓] Connected device (2 available)
• macOS (desktop) • macos • darwin-arm64 • macOS 14.2 23C64 darwin-arm64
• Chrome (web) • chrome • web-javascript • Google Chrome 120.0.6099.129
[✓] Network resources
• All expected network resources are available.
Activity
danagbemava-nc commentedon Dec 29, 2023
Reproducible using the code sample and steps outlined above.
Labeling for further investigation
flutter doctor -v
ericwindmill commentedon Feb 20, 2024
I'm seeing something similar using Intellij, Flutter 3.14, up-to-date Intellij plugin (231.9411).
I'm not using a debugger or running in debug mode. After 2-3 hot restarts, I start seeing an error.
Note my error is the same as 141253, which has been closed.
luckyhandler commentedon Feb 22, 2024
After upgrading my flutter web project to flutter
3.19.1I get on Intellijlike in #141253 when hot restarting the app. It still continues to work.
But
I get into a weird routing state using
router.Not sure what is different in Intellij Build #IC-233.11799.241 and Terminal / or VsCode.
Maybe helps as hint...
UPDATE: I also upgraded
routertogether with flutter from10.0.0to13.2.0--> Downgrading solves the issue for me again. So it's probably also for other folks related torouter.26 remaining items
acpSiam commentedon Apr 2, 2025
Same issue happening here but, in my case, I am pretty sure it's causing by some of my codes. I just cannot find which part of the code is causing this. I wish there was more in-depth debug information available.
graemep-nz commentedon Jun 19, 2025
anilari commentedon Aug 25, 2025
I have same problem with 3.35.1
Assertion failed: org-dartlang-sdk:///lib/_engine/engine/window.dart:99:12
!isDisposed
"Trying to render a disposed EngineFlutterView."
When I try to debug my application it always opens somewhere inside of the framework and distracting my development.
nshahan commentedon Sep 4, 2025
Notes for a future investigation from a random hallway conversation today:
These errors could be caused by scheduling a callback for after a frame renders.
flutter/engine/src/flutter/lib/web_ui/lib/src/engine/frame_service.dart
Lines 90 to 109 in 3a18c94
It looks like this could be scheduling a callback on the JavaScript side which means it could persist after a hot restart.
It sounds like there is an API to schedule a callback for after a frame render. We should experiment and see if we can repro the issues with it.
If that does repro, we could potentially add checks to ensure the callback runs in the same generation of the application or cancel it if it was scheduled before a hot restart of the application and tries to run after.
plchekspend commentedon Sep 18, 2025
Facing the same issue with Flutter 3.35.3
Assertion failed: org-dartlang-sdk:///lib/_engine/engine/window.dart:99:12
!isDisposed
"Trying to render a disposed EngineFlutterView."
Another exception was thrown: Assertion failed: org-dartlang-sdk:///lib/_engine/engine/window.dart:99:12
Facing this on flutter web also i noticed that when i used dialogue on certain screen and when popping that dialogue facing this error logs exception.
Now it logs continuously whichever part go to in app.
eli1stark commentedon Sep 18, 2025
@nshahan
Thank you for the follow-up! This is a framework issue that can be consistently reproduced using the sample code below.
Reproduction steps:
Sample code
Flutter doctor output
Please consider upgrading this from P3 to P2 given its impact on web development, community engagement (👍), and that it's been pending since 2023.
[web] Fix assertion thrown when hot restarting during animation (#175856
[web] Fix assertion thrown when hot restarting during animation (flut…
github-actions commentedon Oct 8, 2025
This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of
flutter doctor -vand a minimal reproduction of the issue.[web] Fix assertion thrown when hot restarting during animation (flut…
[web] Fix assertion thrown when hot restarting during animation (#175…