"Cannot run with sound null safety" Flutter an existing Project?

Question

I had an existing application which i want to modify, I am using following dependencies:

  path_provider: ^2.0.8
  http: ^0.13.4
  html: ^0.15.0
  custom_pop_up_menu: ^1.2.2
  share: ^2.0.4
  connectivity: ^3.0.6
  flutter_swiper: ^1.1.6

Following error, i have even created a new empty project and added the dart files to that project but it is not working now.

    Error: Cannot run with sound null safety, because the following dependencies
don't support null safety:

 - package:flutter_swiper
 - package:plugin_platform_interface
 - package:flutter_page_indicator
 - package:transformer_page_view

try running with no null safety flag: `flutter run --no-sound-null-safety` Similar question: https://stackoverflow.com/q/64917744/5669120 — Ketan Ramteke, Dec 30 '21 at 11:02
Does this answer your question? [Cannot run with sound null safety because dependencies don't support null safety](https://stackoverflow.com/questions/64917744/cannot-run-with-sound-null-safety-because-dependencies-dont-support-null-safety) — Ketan Ramteke, Dec 30 '21 at 11:07

score 3 · Answer 1 · answered Dec 30 '21 at 11:13

3

First upgrade your flutter and packages upto date,

Run flutter pub outdated --mode=null-safety to print all outdated packages. Than,
Run this, flutter pub upgrade --null-safety to upgrade all packages automatically

answered Dec 30 '21 at 11:13

Manishyadav

647
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score 1 · Accepted Answer · answered Dec 30 '21 at 11:03

1

This is because some of the dependencies that you are using not supports null-safety and to solve this you can upgrade your dependencies or use below command to run your application without null-safety.

flutter run --no-sound-null-safety

answered Dec 30 '21 at 11:03

Diwyansh

2,048
1
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8

Downloading Web SDK... 21.8s Downloading CanvasKit... 7.6s Error: No pubspec.yaml file found. This command should be run from the root of your Flutter project... – Qasim Ali Dec 30 '21 at 11:06
1

Go to your project folder then run the command – Diwyansh Dec 30 '21 at 11:08
1

It works in Edit Config args.. – Qasim Ali Dec 30 '21 at 11:37
1

good to hear that – Diwyansh Dec 30 '21 at 11:38

score 0 · Answer 3 · answered Apr 05 '22 at 11:49

Option 1: Upgrade your flutter and packages upto date Run flutter pub outdated --mode=null-safety to display all outdated packages. Then, Run flutter pub upgrade --null-safety to upgrade all packages with no sound null safety

Option 2: Run flutter run --no-sound-null-safety

Option 3: If you want to run your applications with no sound null safety, For VSCode user, add below to settings.json

"dart.flutterRunAdditionalArgs": [
    "--no-sound-null-safety"
],

"Cannot run with sound null safety" Flutter an existing Project?

3 Answers3