After upgrading Flutter to 3.29.3 image.toByteData throws empty Exception

Steps to reproduce

Open Flutter app with flutter version 3.29 on Android emulator
Add code which calls method image.toByteData multiple times in cycle
It is reproducable on emulators and real devices; The bug appears not constantly - for instance, if you will have 10 attempts, it will run 8 times without any errors and it will throw an exception twice
Part of Firebase Crashlytics log is below

        Non-fatal Exception: io.flutter.plugins.firebase.crashlytics.FlutterError: Exception: 
       at _CustomZone.registerBinaryCallback(dart:async)
       at _RouteMapState._initMarkers(route_map.dart:134)
       at _RouteMapState.didUpdateWidget.<fn>(route_map.dart:75)
       at SchedulerBinding._invokeFrameCallback(binding.dart:1438)
       at SchedulerBinding.handleDrawFrame(binding.dart:1365)
       at SchedulerBinding._handleDrawFrame(binding.dart:1204)

It was not reproducable on Flutter 3.27.3 or lower

Expected results

Method image.toByteData doesn't throw any exception, code after it is performing

Actual results

Method image.toByteData throws exception without any desciption

Code sample

Future<BitmapDescriptor?> method() async {
  for (var index = 0; index < 3; index++) {
    await _generateMarker(index);
  }
}

Future<BitmapDescriptor?> _generateMarker(int index) async {
  final markerSize = 28;
  final iconSize = markerSize + (_strokeWidth * 2).round();
  final centerMarker = iconSize / 2;
  final radius = markerSize / 2;

  final backgroundPaint = Paint()..isAntiAlias = true;
  final pictureRecorder = ui.PictureRecorder();
  final canvas = Canvas(pictureRecorder);

  final textSpan = TextSpan(
    text: index.toString(),
    style: TextStyle(
      fontSize: 14,
      fontFamily: 'Inter',
      fontWeight: FontWeight.normal,
      height: 20 / 14,
      letterSpacing: 0,
      textBaseline: TextBaseline.alphabetic,
      decoration: TextDecoration.none,
      leadingDistribution: TextLeadingDistribution.even,
    ),
  );

  final textPainter =
      TextPainter(
        text: textSpan,
        textDirection: TextDirection.ltr,
      )..layout(
        minWidth: 0,
        maxWidth: iconSize.toDouble(),
      );
  backgroundPaint.color = Colors.green;

  canvas.drawCircle(Offset(centerMarker, centerMarker), radius, backgroundPaint);

  textPainter.paint(
    canvas,
    Offset(
      (iconSize - textPainter.width) / 2,
      (iconSize - textPainter.height) / 2,
    ),
  );

  final pic = pictureRecorder.endRecording();
  final img = await pic.toImage(iconSize.toInt(), iconSize.toInt());
  final byteData = await img.toByteData(format: ui.ImageByteFormat.png); //<-- Exception throws here
  final buffer = byteData?.buffer.asUint8List();

  if (buffer == null) return null;

  return BitmapDescriptor.fromBytes(buffer);
}

Screenshots or Video

Screenshots / Video demonstration

[Upload media here]

Logs

E/flutter (14843): [ERROR:flutter/lib/ui/painting/image_encoding_impeller.cc(195)] Failed to submit commands.
I/flutter (14843): [Reporter.error]:
I/flutter (14843): _Exception: Exception: 
I/flutter (14843): dart:async                                                                                 _CustomZone.registerBinaryCallback
I/flutter (14843): package:cargomart/src/presentation/screens/order_route_details/widgets/route_map.dart 134  _RouteMapState._initMarkers
I/flutter (14843): package:cargomart/src/presentation/screens/order_route_details/widgets/route_map.dart 75   _RouteMapState.didUpdateWidget.<fn>
I/flutter (14843): package:flutter/src/scheduler/binding.dart 1442                                            SchedulerBinding._invokeFrameCallback
I/flutter (14843): package:flutter/src/scheduler/binding.dart 1369                                            SchedulerBinding.handleDrawFrame
I/flutter (14843): package:flutter/src/scheduler/binding.dart 1208                                            SchedulerBinding._handleDrawFrame

Flutter Doctor output

Doctor output

[✓] Flutter (Channel stable, 3.32.5, on macOS 15.3 24D60 darwin-arm64 (Rosetta), locale ru-RU)
[✓] Android toolchain - develop for Android devices (Android SDK version 35.0.0)
[✓] Xcode - develop for iOS and macOS (Xcode 16.4)
[✓] Chrome - develop for the web
[✓] Android Studio (version 2023.1)
[✓] VS Code (version 1.83.1)
[✓] Connected device (3 available)
[✓] Network resources

• No issues found!

@lighthead9288

@lighthead9288 Please provide us minimal but complete runnable and reproducible code sample (ex: main.dart) that shows the reported behavior.

flutter_create_markers_application.zip

Steps to reproduce:

Unzip this archive
Open folder containing this flutter project, run command flutter pub get
There are 2 screens in this project - first one has button 'Open', second one contains a widget with a geographic map. We draw marker points on the map widget at the second screen.
Try to open and close second screen multiple times - if an attempt will lead to success, you will see 2 markers(green and red) on the map; if an attempt will be unsuccessfull - you will see a Snackbar and a specific text in debug console.
The program throws an _Exception at this string:

byteData = await img.toByteData(format: ui.ImageByteFormat.png)

@lighthead9288

Thanks for the repo @lighthead9288, I do see the error in the snackbar:

But looking at the repo again, I see that there are some external library / implementations being used. Is it possible to narrow down the issue with google_maps_flutter and without external plugins ?

Without additional information, we are unfortunately not sure how to resolve this issue. We are therefore reluctantly going to close this bug for now.
If you find this problem please file a new issue with the same description, what happens, logs and the output of 'flutter doctor -v'. All system setups can be slightly different so it's always better to open new issues and reference the related ones.
Thanks for your contribution.

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.

@chinmaygarde

Reproduced this using the attached app on an Android emulator running Impeller/GLES.

It reproduces more easily if I patch the app's _generatePointMarker to make repeated calls to Image.toByteData during the initial press of the "Open" button.

The issue is caused by a race between the raster thread merger and the Impeller image encoder. The sequence is:

On the IO thread, a task calls EncodeImageAndInvokeDataCallback
- EncodeImageAndInvokeDataCallback queues a task to the raster thread that will rasterize the image using Impeller.
On the raster thread, a task calls RasterThreadMerger::MergeWithLease
- MergeWithLease merges the raster thread into the platform thread. Any pending raster tasks will be executed on the platform thread.
The raster task queued by EncodeImageAndInvokeDataCallback executes on the platform thread.
- But at this point the platform thread may not have a current EGL context.
- If the platform thread has no EGL context, then when the task submits an Impeller command buffer ReactorGLES::React will fail the CanReactOnCurrentThread check.
- ImageEncodingImpeller::ConvertDlImageToSkImage will log the Failed to submit commands error, and the app's Image.toByteData call will throw an exception.

The issue does not always happen because another raster task (such as an AcquireFrame) may run after the MergeWithLease and before the ImageEncodingImpeller task. If that task makes an EGL context current on the platform thread, then when the ImageEncodingImpeller task runs it will be able to execute GLES commands.

Not sure what would be the best way to resolve this. It looks like the raster thread merger does not have a way to immediately make an EGL context current on the the merged thread.
So instead ImageEncodingImpeller may need to use the SnapshotController::Delegate to activate an EGL context (similar to how the Skia image encoder implementation does this through SnapshotControllerSkia::ConvertToRasterImage)

@chinmaygarde

Ensure that the raster thread has an EGL context before submitting th…

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.

Ensure that the raster thread has an EGL context before submitting th…

Navigation Menu

Repository navigation

After upgrading Flutter to 3.29.3 image.toByteData throws empty Exception #171946

Steps to reproduce

Expected results

Actual results

Code sample

Screenshots or Video

Logs

Flutter Doctor output

6 remaining items

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

After upgrading Flutter to 3.29.3 image.toByteData throws empty Exception #171946

Description

Steps to reproduce

Expected results

Actual results

Code sample

Screenshots or Video

Logs

Flutter Doctor output

Activity

darshankawar commented on Jul 10, 2025

lighthead9288 commented on Jul 11, 2025

darshankawar commented on Jul 14, 2025

github-actions commented on Aug 4, 2025

github-actions commented on Aug 18, 2025

jason-simmons commented on Sep 6, 2025

6 remaining items

github-actions commented on Oct 2, 2025

Metadata

Metadata

Assignees

Labels

Type

Projects

Milestone

Relationships

Development

Issue actions