Flutter FirebaseError: 'FirebaseAppPlatform.verifyExtends' Member Not Found

Problem Statement

When working with Firebase plugins in Flutter, you may encounter an error stating:
Member not found: 'FirebaseAppPlatform.verifyExtends'. FirebaseAppPlatform.verifyExtends(_delegate);

This error typically occurs after:

• Installing/updating Firebase plugins (firebase_core, firebase_auth, etc.)
• Running flutter pub get or flutter run
• Cleaning your project (flutter clean)

Root Cause: The error stems from version incompatibility between Firebase packages. Specifically, some Firebase plugins depend on firebase_core_platform_interface version 4.5.2 which introduced a breaking change (renaming verifyExtends to verify). Using incompatible plugin versions triggers this issue.

Recommended Solutions

Solution 1: Update All Major Package Versions (Preferred)

The cleanest fix is to upgrade your Firebase packages to versions compatible with firebase_core_platform_interface: 4.5.2+.

# Update packages to their latest compatible versions
flutter pub upgrade --major-versions

# Clean and rebuild
flutter clean
flutter pub get

# For iOS projects (clean pods)
cd ios
pod deintegrate
rm Podfile.lock
cd ..
flutter pub get
cd ios && pod install --repo-update

# Finally run your app
flutter run

Why this works

The upgrade --major-versions command updates all packages to their latest major releases, resolving dependency conflicts automatically. This approach:

• Eliminates version incompatibilities
• Applies latest security patches
• Avoids temporary workarounds

Solution 2: Pin Platform Interface Version (Temporary Workaround)

If immediate upgrading isn't feasible, pin the problematic interface to 4.5.1:

# Add this to your pubspec.yaml
dependency_overrides:
  firebase_core_platform_interface: 4.5.1

IMPORTANT

While this fixes the immediate error, it's a temporary solution that:

1. May cause future conflicts with newer plugins
2. Prevents you from receiving security updates
3. Should be replaced with Solution 1 as soon as possible

After making the change:

flutter clean
flutter pub get

Verifying Firebase Versions

Always verify compatible versions on pub.dev. Recommended current versions:

• firebase_core: ^2.30.0
• firebase_auth: ^5.0.0
• cloud_firestore: ^4.15.0

Check firebase_core_platform_interface versions for compatibility.

View FlutterFire version compatibility table

Common Pitfalls to Avoid

❌ Manually editing lockfiles

# pubspec.lock (Don't edit manually!)
firebase_core_platform_interface: ^4.5.2  # AVOID CHANGING THIS DIRECTLY

❌ Editing Firebase source files Replacing FirebaseAppPlatform.verifyExtends() with .verify() in Dart files causes:

• Unmaintainable code
• Breaks in future updates
• Collaboration conflicts

❌ Incomplete cleaning Always run flutter clean after dependency changes:

# Android/iOS
flutter clean

# Additional iOS cleanup
cd ios && rm -rf Pods Podfile.lock

❌ Selective plugin updates
Update all Firebase plugins together:

# Don't update only one plugin
dependencies:
  firebase_core: ^2.30.0
  firebase_auth: ^5.0.0   # Update all, not just one
  cloud_firestore: ^4.15.0

Best Practices for Firebase in Flutter

1. Use FlutterFire CLI to manage compatibility:

dart pub global activate flutterfire_cli
flutterfire configure

2. Regularly check for updates:

flutter pub outdated

3. Always test after dependency changes:

flutter clean && flutter run

Pro Tip

For CI/CD pipelines, add flutter pub upgrade --major-versions and flutter clean to your build scripts to prevent version drift.

Conclusion

The Member not found: 'FirebaseAppPlatform.verifyExtends' error results from Firebase version mismatches. The optimal solution is to upgrade packages using flutter pub upgrade --major-versions. For temporary fixes, pinning firebase_core_platform_interface: 4.5.1 works but should be replaced with full upgrades promptly. Always verify plugin compatibility at pub.dev and leverage flutter clean after dependency changes.