Expected a value of type 'List<Widget>', but got one of type 'List<Widget?>'

[madhusudhanv255]

I am getting this error for using simple usage code for cupertino App.

Expected a value of type 'List', but got one of type 'List<Widget?>'
The relevant error-causing widget was:
InnerDrawer-[LabeledGlobalKey#5dd34]
InnerDrawer:file:///Applications/MAMP/htdocs/angularjs/owlinvest/mobile/adv_basics/lib/dashboard.dart:45:12

When the exception was thrown, this was the stack:
dart-sdk/lib/internal/js_dev_runtime/private/ddc_runtime/errors.dart 288:49 throw
dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/errors.dart 121:3 castError
dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/operations.dart 529:12 cast
dart-sdk/lib/_internal/js_dev_runtime/private/ddc_runtime/classes.dart 638:14 as_C
packages/flutter_inner_drawer/inner_drawer.dart 437:21 [_scaffold]
packages/flutter_inner_drawer/inner_drawer.dart 614:55 build
packages/flutter/src/widgets/framework.dart 5198:27 build
packages/flutter/src/widgets/framework.dart 5086:15 performRebuild
packages/flutter/src/widgets/framework.dart 5251:11 performRebuild
packages/flutter/src/widgets/framework.dart 4805:7 rebuild
packages/flutter/src/widgets/framework.dart 5068:5 [_firstBuild]
packages/flutter/src/widgets/framework.dart 5242:11 [_firstBuild]
packages/flutter/src/widgets/framework.dart 5062:5 mount
packages/flutter/src/widgets/framework.dart 3971:15 inflateWidget
packages/flutter/src/widgets/framework.dart 3708:18 updateChild
packages/flutter/src/widgets/framework.dart 5111:16 performRebuild
packages/flutter/src/widgets/framework.dart 5251:11 performRebuild
packages/flutter/src/widgets/framework.dart 4805:7 rebuild
packages/flutter/src/widgets/framework.dart 5068:5 [_firstBuild]
packages/flutter/src/widgets/framework.dart 5242:11 [_firstBuild]
packages/flutter/src/widgets/framework.dart 5062:5 mount
packages/flutter/src/widgets/framework.dart 3971:15 inflateWidget
packages/flutter/src/widgets/framework.dart 3708:18 updateChild
packages/flutter/src/widgets/framework.dart 5111:16 performRebuild
packages/flutter/src/widgets/framework.dart 4805:7 rebuild
packages/flutter/src/widgets/framework.dart 5068:5 [_firstBuild]
packages/flutter/src/widgets/framework.dart 5062:5 mount
packages/flutter/src/widgets/framework.dart 3971:15 inflateWidget
packages/flutter/src/widgets/framework.dart 3708:18 updateChild
packages/flutter/src/widgets/framework.dart 5111:16 performRebuild
packages/flutter/src/widgets/framework.dart 5251:11 performRebuild
packages/flutter/src/widgets/framework.dart 4805:7 rebuild
packages/flutter/src/widgets/framework.dart 5068:5 [_firstBuild]
packages/flutter/src/widgets/framework.dart 5242:11 [_firstBuild]
packages/flutter/src/widgets/framework.dart 5062:5 mount
packages/flutter/src/widgets/framework.dart 3971:15 inflateWidget
packages/flutter/src/widgets/framework.dart 3708:18 updateChild
packages/flutter/src/widgets/framework.dart 5111:16 performRebuild
packages/flutter/src/widgets/framework.dart 4805:7 rebuild
packages/flutter/src/widgets/framework.dart 5068:5 [_firstBuild]
packages/flutter/src/widgets/framework.dart 5062:5 mount
packages/flutter/src/widgets/framework.dart 3971:15 inflateWidget
packages/flutter/src/widgets/framework.dart 3708:18 updateChild
packages/flutter/src/widgets/framework.dart 5111:16 performRebuild
packages/flutter/src/widgets/framework.dart 4805:7 rebuild
packages/flutter/src/widgets/framework.dart 5068:5 [_firstBuild]
packages/flutter/src/widgets/framework.dart 5062:5 mount
packages/flutter/src/widgets/framework.dart 3971:15 inflateWidget
packages/flutter/src/widgets/framework.dart 3708:18 updateChild
packages/flutter/src/widgets/binding.dart 1240:16 [_rebuild]
packages/flutter/src/widgets/binding.dart 1209:5 mount
packages/flutter/src/widgets/binding.dart 1156:16
packages/flutter/src/widgets/framework.dart 2720:19 buildScope
packages/flutter/src/widgets/binding.dart 1155:12 attachToRenderTree
packages/flutter/src/widgets/binding.dart 987:24 attachRootWidget
packages/flutter/src/widgets/binding.dart 968:7
dart-sdk/lib/_internal/js_dev_runtime/private/isolate_helper.dart 48:19 internalCallback

════════════════════════════════════════════════════════════════════════════════════════════════════
Another exception was thrown: Unexpected null value.

Below is pubspec.yaml

name: adv_basics
description: A new Flutter project.
version: 1.0.0+1

environment:
sdk: '>=3.0.5 <4.0.0'

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: ^1.0.2
http: ^0.13.5
local_auth: ^2.1.6
flutter_session_manager: ^1.0.3
adaptive_theme: ^3.3.0
flutter_dotenv: "^5.1.0"
flutter_inner_drawer: "^1.0.0+1"

dev_dependencies:
flutter_test:
sdk: flutter

flutter_lints: ^2.0.0
flutter_fusioncharts: ^1.0.2

uses-material-design: true

To add assets to your application, add an assets section, like this:

assets:
- assets/images/quiz-logo.png
- assets/environments/.env_production
- assets/environments/.env_staging
- assets/environments/.env_dev
- assets/data/countries.json
- fusioncharts/integrate/index_local.html
- fusioncharts/integrate/index_cdn.html
- fusioncharts/integrate/index.js
- fusioncharts/core/fusioncharts.charts.js
- fusioncharts/core/fusioncharts.overlappedbar2d.js
- fusioncharts/core/fusioncharts.timeseries.js
- fusioncharts/core/fusioncharts.treemap.js
- fusioncharts/core/fusioncharts.powercharts.js
- fusioncharts/core/fusioncharts.maps.js
- fusioncharts/core/fusioncharts.zoomscatter.js
- fusioncharts/core/fusioncharts.js
- fusioncharts/core/fusioncharts.excelexport.js
- fusioncharts/core/fusioncharts.widgets.js
- fusioncharts/core/fusioncharts.zoomline.js
- fusioncharts/core/fusioncharts.gantt.js
- fusioncharts/core/fusioncharts.overlappedcolumn2d.js
- fusioncharts/core/fusioncharts.vml.js
- fusioncharts/core/fusioncharts.accessibility.js