Flutter: Unimplemented handling of missing static target

Flutter Problem Overview

I am running my first Flutter project
I created a sample project and I was able to run the app in simulator

I have edited the file main.dart

main.dart

import 'package:flutter/material.dart';

void main() => runApp(MaterialApp(home: Text('Hello World')));

Now I am getting the error :

pubspec.yaml

name: flutter_app
description: A new Flutter application.

# The following defines the version and build number for your application.
# A version number is three numbers separated by dots, like 1.2.43
# followed by an optional build number separated by a +.
# Both the version and the builder number may be overridden in flutter
# build by specifying --build-name and --build-number, respectively.
# In Android, build-name is used as versionName while build-number used as versionCode.
# Read more about Android versioning at https://developer.android.com/studio/publish/versioning
# In iOS, build-name is used as CFBundleShortVersionString while build-number used as CFBundleVersion.
# Read more about iOS versioning at
# https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
version: 1.0.0+1

environment:
  sdk: ">=2.1.0 <3.0.0"

dependencies:
  flutter:
    sdk: flutter

  # The following adds the Cupertino Icons font to your application.
  # Use with the CupertinoIcons class for iOS style icons.
  cupertino_icons: ^0.1.2

dev_dependencies:
  flutter_test:
    sdk: flutter


# For information on the generic Dart part of this file, see the
# following page: https://dart.dev/tools/pub/pubspec

# The following section is specific to Flutter.
flutter:

  # The following line ensures that the Material Icons font is
  # included with your application, so that you can use the icons in
  # the material Icons class.
  uses-material-design: true

  # To add assets to your application, add an assets section, like this:
  # assets:
  #  - images/a_dot_burr.jpeg
  #  - images/a_dot_ham.jpeg

  # An image asset can refer to one or more resolution-specific "variants", see
  # https://flutter.dev/assets-and-images/#resolution-aware.

  # For details regarding adding assets from package dependencies, see
  # https://flutter.dev/assets-and-images/#from-packages

  # To add custom fonts to your application, add a fonts section here,
  # in this "flutter" section. Each entry in this list should have a
  # "family" key with the font family name, and a "fonts" key with a
  # list giving the asset and other descriptors for the font. For
  # example:
  # fonts:
  #   - family: Schyler
  #     fonts:
  #       - asset: fonts/Schyler-Regular.ttf
  #       - asset: fonts/Schyler-Italic.ttf
  #         style: italic
  #   - family: Trajan Pro
  #     fonts:
  #       - asset: fonts/TrajanPro.ttf
  #       - asset: fonts/TrajanPro_Bold.ttf
  #         weight: 700
  #
  # For details regarding fonts from package dependencies,
  # see https://flutter.dev/custom-fonts/#from-packages

Flutter Solutions

Solution 1 - Flutter

The same error occurred for me at first ... but it worked when I did a 'hot restart'

Solution 2 - Flutter

Just compile the project again and it will work. The error occurs because static variables are hard compiled on the executable and are not dynamic. If you hot reload the changes, it will not rebuild the executable (apk), so that's why you need to rebuild the app.

Solution 3 - Flutter

Your code works for me...

Have you tried a hot restart? The shortcut is CTRL+SHIFT+\ or just click the button with the green circle-arrow in the console-window

I'm not sure what that error is, since I can't replicate it. However, this is more like what your app should look like. Give this a shot and see if it works.

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Text('Hello World'),
    );
  }
}

Solution 4 - Flutter

Just delete the build and recompile. It worked for me. Use the following code:

flutter clean
flutter run

Solution 5 - Flutter

Usually, a Full App Restart is required after a heavy logic change, as transforming a StatelessWidget into StatefulWidget. Check André Glatzl answer

In Android Studio use the Flutter Hot Restart

Solution 6 - Flutter

A hot restart will work. But the source of the problem might be as follows.

You've created new project. You've deleted boilerplate code and try to modify without a stateful or stateless widget. Flutter tries to rebuild widgets under build() method. But when you hot reload, flutter might not resolve what you've updated.

Another example of such error is, when we create a new static variable(static String token = "abc";) in one Class (like constants.dart) and try to reference them in another screen (constants.token), flutter failed to resolve such static things when we hotreload. but it work fine when we hotrestart.

Solution 7 - Flutter

One of the reasons this happens is you are running the app for the first time and then you make some changes and reload again. Without reloading, stop the execution, and again run the app from scratch, this error won't come.

Solution 8 - Flutter

Restarting the app worked in my case.

Solution 9 - Flutter

Run this command again

'flutter run'

should work

Solution 10 - Flutter

You changed the myApp and created your own MaterialApp so all you have to do is after changing the name into MaterialApp instead of hot restart click the play button. It will work. Thanks

Solution 11 - Flutter

Just press the red stop button and click the play button again. It will work :)

Solution 12 - Flutter

As other answers mention, you can 'hot reload' or rebuild your app to solve this issue.

But the reason why I got this error, was that I have edited the pubspec.yaml file, when editing the pubspec.yaml file, you should stop and rebuild the entire app.

Solution 13 - Flutter

Navigate to your lib folder where your main.dart file is and run the commands below:

PS C:\Users\mobile_app\lib> flutter clean

PS C:\Users\mobile_app\lib> flutter pub get

PS C:\Users\mobile_app\lib> flutter run

although if you are having null safety issues I would prefer you debug your application first. In my encounters this error is of a result of trying to run a class component outside a the Static Widget with context hence the class is loaded before build time making the application fail to start.

Solution 14 - Flutter

Check your import. It should be import 'package:your_app...' not import 'file://C/path/your_app/

Solution 15 - Flutter

I also faced the same situation, I fixed it by running the app again, This issue is caused when you applied a lot of change to your code and pressed the hot reload button.

Content Type	Original Author	Original Content on Stackoverflow
Question	Devrath	View Question on Stackoverflow
Solution 1 - Flutter	Hitesh Pandey	View Answer on Stackoverflow
Solution 2 - Flutter	André Glatzl	View Answer on Stackoverflow
Solution 3 - Flutter	Joshua Craven	View Answer on Stackoverflow
Solution 4 - Flutter	Kalana Mihiranga	View Answer on Stackoverflow
Solution 5 - Flutter	dianakarenms	View Answer on Stackoverflow
Solution 6 - Flutter	Cnu Federer	View Answer on Stackoverflow
Solution 7 - Flutter	Jananath Banuka	View Answer on Stackoverflow
Solution 8 - Flutter	Naimur Hasan	View Answer on Stackoverflow
Solution 9 - Flutter	Khuong	View Answer on Stackoverflow
Solution 10 - Flutter	Ghanashyam	View Answer on Stackoverflow
Solution 11 - Flutter	Mano Haran	View Answer on Stackoverflow
Solution 12 - Flutter	MendelG	View Answer on Stackoverflow
Solution 13 - Flutter	Lamech Desai	View Answer on Stackoverflow
Solution 14 - Flutter	TSR	View Answer on Stackoverflow
Solution 15 - Flutter	Emmanuel Ametepee	View Answer on Stackoverflow