Flutter, after upgrading to 3.10, "Future isn't a type"

Question

After upgrading flutter with flutter upgrade to 3.10

All my (previously working) Futures stopped working. Every single future is underlined with red saying "Future isn't a type".

What can I do to fix this? Clearly Future hasn't been removed.

Gabrila

Try running flutter pub get in terminal – Jarodjarosite

Answer 1

I had the same problem, what helped me to solve it was:

• in AS go to Settings > Languages ​​and Frameworks > flutter and set Flutter SDK path to your new version path and apply
  
• make sure that Settings > Languages ​​and Frameworks > dart is using the correct version corresponding to your new version of flutter SDK
  

Note:
I am using Android Studio.
I am using FVM to manage SDK versions
my update was from 3.3.5 to 3.13.2 (Flutter SDK) - (2.18.2 to 3.1.0 (Dart))

I hope it helps someone

Vinosity

Answer 2

Just reloading VsCode fixed the issue for me

Edd

Answer 3

This was happing to me too after upgrade to 3.10.

I am using VS Code. After opening with Android Studio, I was able to build it without any problem.

Going back to VS Code, and it starts to work again. 😃

Tiffin

you save my life, in my case i use fvm for version 3.10.6 – Diversification

Answer 4

add "import 'dart:async';" in your code and change "future" to "FutureOr"

Admetus

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Answer 5

Once you upgrade to Flutter 3.10, make sure you change the Flutter SDK environment version in pubspec.yaml file

Change From:

environment:
  sdk: 'existing_version'

To:

environment:
  sdk: '>=3.0.3 <4.0.0' //TODO: Change Version

After this run,

flutter pub get
flutter pub upgrade

Idelson

Answer 6

I’m using FVM to switch from SDK 2.10.5 to 3.24.2, but I get this error:

Future isn't a type. Try correcting the name to match an existing type.

Initially, I tried importing dependencies and updating the SDK environment in pubspec.yaml in VSCode, but nothing worked. Then, I opened the same project in Android Studio Koala (the newer version), and it ran successfully without any code changes.

command I used in Android Studio(already select sdk using fvm):

fvm flutter pub get

and

fvm flutter run

So, I can assume this issue might be caused by the IDE or Flutter/Dart settings in the IDE(both IDEs have the same SDK path and the same versions of Flutter and Dart installed).

Tressietressure

Answer 7

Flutter clean Flutter pub get

I think that will work for You

Arella

Doesn't work unfortunely – Gabrila