[Solved] FlutterError: Unable to load asset

Question

Asked by Matthias on December 06, 2018 (source).

This is the folder structure of my app

.idea
.vscode
android
build
fonts
 Oxygen-Bold.tff
 Oxygen-Light.tff
 Oxygen-Regular.tff
images
 pizza0.png
 pizza1.png
ios
lib
 ui
  home.dart
 main.dart
test
.gitignore
.metadata
.packages
app_widgets.iml
pubspec.lock
pubspec.yaml
README.md

In my pubspec.yaml file, I load the fonts and assets like this

flutter:

uses-material-design: true

assets:
  - images/pizza0.png
  - images/pizza1.png

fonts:
  - family: Oxygen
    fonts:
      - asset: fonts/Oxygen-Regular.ttf
      - asset: fonts/Oxygen-Bold.ttf
        weight: 700
      - asset: fonts/Oxygen-Light.ttf
        weight: 300

I'm not getting any errors for this pubspec.yaml, and running flutter packages get gives an exit code of 0.

In my home.dart I have the following class:

class PizzaImageWidget extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    AssetImage pizzaAsset = AssetImage('images/pizza0.png');
    Image image = Image(image: pizzaAsset, width: 400, height: 400);
    return Container(
      child: image,
    );
  }
}

Which I use elsewhere, in order to show the image (code omitted):

        ),
        PizzaImageWidget(),
      ],

The building gives no errors. Flutter Doctor -v doesn't give any errors, neither does Flutter Analyze -v. The .apk seems to build just fine but when the app opens up on my phone I get the following error in asset_bundle.dart:

Exception has occurred. FlutterError (Unable to load asset: images/pizza0.png)

The error is thrown by this class in the asset_bundle.dart file:

/// An [AssetBundle] that loads resources using platform messages.
class PlatformAssetBundle extends CachingAssetBundle {
  @override
  Future<ByteData> load(String key) async {
    final Uint8List encoded = utf8.encoder.convert(Uri(path: Uri.encodeFull(key)).path);
    final ByteData asset =
        await BinaryMessages.send('flutter/assets', encoded.buffer.asByteData());
    if (asset == null)
      throw FlutterError('Unable to load asset: $key');
    return asset;
  }
}

This happens both for the pizza0.png file as well as the pizza1.png file. The files are visible in the tree structure, both in Windows Explorer as in VS Code. The font assets load without issue.

This is the output I am getting when running Flutter Run -v:

[+1068 ms] I/flutter ( 6489): ══╡ EXCEPTION CAUGHT BY IMAGE RESOURCE SERVICE ╞════════════════════════════════════════════════════ [ +9 ms] I/flutter ( 6489): The following assertion was thrown resolving an image codec: [ +2 ms] I/flutter ( 6489): Unable to load asset: images/pizza0.png [ +2 ms] I/flutter ( 6489): [ +1 ms] I/flutter ( 6489): When the exception was thrown, this was the stack: [ +2 ms] I/flutter ( 6489): #0 PlatformAssetBundle.load (package:flutter/src/services/asset_bundle.dart:221:7) [ +1 ms] I/flutter ( 6489): [ +1 ms] I/flutter ( 6489): #1 AssetBundleImageProvider._loadAsync (package:flutter/src/painting/image_provider.dart:429:44) [ +1 ms] I/flutter ( 6489): [ +1 ms] I/flutter ( 6489): #2 AssetBundleImageProvider.load (package:flutter/src/painting/image_provider.dart:414:14) [ +1 ms] I/flutter ( 6489): #3 ImageProvider.resolve.. (package:flutter/src/painting/image_provider.dart:267:86) [ +4 ms] I/flutter ( 6489): #4 ImageCache.putIfAbsent (package:flutter/src/painting/image_cache.dart:143:20) [ +3 ms] I/flutter ( 6489): #5 ImageProvider.resolve. (package:flutter/src/painting/image_provider.dart:267:63) [ +3 ms] I/flutter ( 6489): (elided 8 frames from package dart:async) [ +1 ms] I/flutter ( 6489): [ +1 ms] I/flutter ( 6489): Image provider: AssetImage(bundle: null, name: "images/pizza0.png") [ +3 ms] I/flutter ( 6489): Image key: AssetBundleImageKey(bundle: PlatformAssetBundle#20fc8(), name: "images/pizza0.png", [ +1 ms] I/flutter ( 6489): scale: 1.0) [ +2 ms] I/flutter ( 6489): ════════════════════════════════════════════════════════════════════════════════════════════════════

Answer

Question answered by diegoveloper (source).

You should consider the indentation for assets

flutter:

  assets:
    - images/pizza1.png
    - images/pizza0.png

More details:

flutter:

[2 whitespaces or 1 tab]assets:
[4 whitespaces or 2 tabs]- images/pizza1.png
[4 whitespaces or 2 tabs]- images/pizza0.png
ASSETS FLUTTER
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