Flutter Error 03: Firebase core plugin in Flutter app cannot load the FirebaseOptions

Flutter Error 03: Firebase core plugin in your Flutter app cannot load the FirebaseOptions from the values.xml file.

The error you're encountering occurs because the Firebase core plugin in your Flutter app cannot load the FirebaseOptions from the values.xml file. This typically points to a configuration issue in your Firebase setup.

Steps to Resolve:

1. Verify google-services.json Configuration:

• Ensure the google-services.json file is correctly added to the android/app/ directory.
• Double-check that the file matches your app's package name in the Firebase Console.

2. Check values.xml File:

• Open the file at android/app/src/main/res/values/values.xml.
• Ensure Firebase-related fields (e.g., google_api_key, default_web_client_id) are present and correct. These values are generated automatically from the google-services.json file.

3. Add the Google Services Plugin:

• Open the root android/build.gradle file and ensure this line is present:

  classpath 'com.google.gms:google-services:4.3.15' // Use the latest version
  

• In android/app/build.gradle, ensure you have:

  apply plugin: 'com.google.gms.google-services'
  

4. Initialize Firebase in Flutter:

• Ensure Firebase is initialized in your main.dart file:

  void main() async {
    WidgetsFlutterBinding.ensureInitialized();
    await Firebase.initializeApp();
    runApp(MyApp());
  }
  

5. Check Dependency Compatibility:

• Open pubspec.yaml and ensure your Firebase dependencies are up to date:

  dependencies:
    firebase_core: ^latest_version
    firebase_auth: ^latest_version
    # Add other Firebase dependencies as needed
  

• Run flutter pub get to install them.

6. Clean and Rebuild the Project:

• Run the following commands to clear any cached issues:

  flutter clean
  flutter pub get
  flutter build apk
  

7. Debug with Stacktrace:

• The stack trace indicates the issue originates in FlutterFirebaseCorePlugin. Focus on verifying your Firebase setup and ensuring the environment matches the Firebase Console's configurations.

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If you've completed the above steps and the issue persists, the most common causes are:

• Mismatch in app package name: Ensure the google-services.json file was generated for the exact package name defined in your AndroidManifest.xml.
• Incomplete or corrupt google-services.json file: Re-download it from the Firebase Console.

For more detailed troubleshooting, consult the official Firebase Flutter setup guide.