Flutter Web Text Input Assertion Failure on Click in Chrome

Problem Statement

When developing a Flutter web application using Flutter 3.27.0 and Dart 3.6.0, a specific runtime error occurs during debugging in Chrome (version 131+):

dart

DartError: Assertion failed:
targetElement == domElement
"The targeted input element must be the active input element"

This error triggers when clicking on a text input field in a Flutter web app, disrupting typical form interaction. Key characteristics of the issue:

Environment: macOS (Apple M2), VS Code 1.95.3, Chrome 131.0.6778.139
Reproduction consistency: Occurs in local projects built with Flutter 3.27.0 but not in the official Flutter API embedded examples
Core error message: Points to a discrepancy in DOM elements handling text input focus (targetElement vs domElement)
Code unaffected: The issue persists even when using exact code samples from Flutter's official documentation

The primary impact is broken text field interaction in Flutter web apps during development.

Solution: Update Flutter to Version 3.27.2 or Higher

This issue is a confirmed regression introduced in Flutter 3.27.0 that was fixed in version 3.27.2. The fix is now available in the stable release channel.

Steps to Resolve

Update your Flutter installation:
bash
```
flutter upgrade
```

Verify your new version:

bash

flutter --version

Ensure you have at least:

Flutter 3.27.2 • channel stable
Dart 3.6.0

Clean and rebuild your project:
bash
```
flutter clean
flutter run -d chrome
```

Confirming the Fix

After updating, the error should no longer occur when interacting with text input fields. Verify by clicking on form fields in your application during debugging sessions.

Root Cause

This regression was caused by changes in Flutter's web engine in version 3.27.0 that introduced an assertion failure in pointer event handling. Specifically:

DOM element focus management inconsistencies occurred when text inputs were activated
The engine incorrectly validated active input elements before processing events
Official documentation examples were unaffected because they use older Flutter versions via DartPad (typically v3.24.5)

The issue was tracked and resolved in the Flutter GitHub repository: flutter/flutter#160155

If You Can't Update Immediately

If updating isn't feasible, temporary workarounds include:

Use Flutter 3.24.5:
bash
```
flutter version 3.24.5
```
Switch to the master channel (with caution, as it may be unstable):
bash
```
flutter channel master
flutter upgrade
```

However, these are temporary solutions. Updating to 3.27.2+ is the recommended approach.

Best Practices for Avoiding Similar Issues

Monitor Flutter Release Notes: Check Flutter's stable release notes before upgrading
Reproduce Using Minimal Code: When encountering issues, test with minimal examples from documentation
Check GitHub Issues: Search existing reports before filing new tickets
Stable Channel Preference: Avoid living on master for production development unless troubleshooting specific issues

Flutter's web support continues to mature, but regressions occasionally occur during major updates. Staying updated with stable releases while being aware of known issues provides the most reliable development experience.

Related Posts

Flutter Web Text Input Assertion Failure on Click in Chrome ​

Problem Statement ​

Solution: Update Flutter to Version 3.27.2 or Higher ​

Steps to Resolve ​

Confirming the Fix ​

Root Cause ​

Best Practices for Avoiding Similar Issues ​