Firebase Crashlytics issue on .NET MAUI iOS - GoogleService-Info.plist not detected

Hi Nancy Vo (WICLOUD CORPORATION),

I am facing an issue with Firebase Crashlytics on my .NET MAUI iOS application.

Previously, based on your suggestion, I added the following configuration in my .csproj to include the correct GoogleService-Info.plist based on the configuration:

<ItemGroup Condition="'$(TargetFramework)' == 'net10.0-ios' and ('$(Configuration)' == 'MDU' or '$(Configuration)' == 'UATMDU')">
    <BundleResource Include="Platforms\iOS\MDU\GoogleService-Info.plist">
        <Link>GoogleService-Info.plist</Link>
    </BundleResource>
</ItemGroup>

<ItemGroup Condition="'$(TargetFramework)' == 'net10.0-ios' and ('$(Configuration)' == 'DDU' or '$(Configuration)' == 'UATDDU')">
    <BundleResource Include="Platforms\iOS\DDU\GoogleService-Info.plist">
        <Link>GoogleService-Info.plist</Link>
    </BundleResource>
</ItemGroup>

In MauiProgram.cs, I am initializing Firebase like this:

private static MauiAppBuilder RegisterFirebaseServices(this MauiAppBuilder builder)
{
#if IOS || ANDROID
    builder.ConfigureLifecycleEvents(events =>
    {
#if IOS
        events.AddiOS(iOS => iOS.WillFinishLaunching((_, _) =>
        {
            try
            {
                CrossFirebase.Initialize(CreateCrossFirebaseSettings());
                CrossFirebaseCrashlytics.Current.SetCrashlyticsCollectionEnabled(true);
                CrossFirebaseCrashlytics.Current.SendUnsentReports();

                Runtime.MarshalManagedException += (_, args) =>
                {
                    args.ExceptionMode = MarshalManagedExceptionMode.UnwindNativeCode;
                };

                AppDomain.CurrentDomain.UnhandledException += (_, args) =>
                {
                    if (args.ExceptionObject is Exception ex)
                    {
                        CrossFirebaseCrashlytics.Current.Log(
                            $"Fatal: {ex.GetType().Name}: {ex.Message}");

                        CrossFirebaseCrashlytics.Current.RecordException(ex);
                    }
                };
            }
            catch (Exception ex)
            {
                FirebaseInitError = $"{ex.GetType().Name}: {ex.Message}";
                System.Diagnostics.Debug.WriteLine($"Firebase init error: {ex}");
            }

            return true;
        }));
#elif ANDROID
        events.AddAndroid(android => android.OnCreate((activity, _) =>
        {
            CrossFirebase.Initialize(
                activity,
                () => Microsoft.Maui.ApplicationModel.Platform.CurrentActivity,
                CreateCrossFirebaseSettings()
            );

            FirebaseAnalyticsImplementation.Initialize(activity);
        }));
#endif
    });

    builder.Services.AddSingleton(_ => CrossFirebaseAnalytics.Current);
    builder.Services.AddSingleton(_ => CrossFirebaseCrashlytics.Current);
#endif

    return builder;
}

#if IOS || ANDROID
private static CrossFirebaseSettings CreateCrossFirebaseSettings()
{
    return new CrossFirebaseSettings(
        isAnalyticsEnabled: true,
        isCrashlyticsEnabled: true
    );
}
#endif

I am getting the following exception when CrossFirebase.Initialize() is called:

ObjCRuntime.ObjCException: Objective-C exception thrown.
Name: com.firebase.core
Reason: `FirebaseApp.configure()` could not find a valid GoogleService-Info.plist in your project.
Please download one from https://console.firebase.google.com/.

at Firebase.Core.App.Configure()
at Plugin.Firebase.Bundled.Platforms.iOS.CrossFirebase.Initialize(...)
at MDU.MauiProgram...RegisterFirebaseServices...

The important point is that:

The Bundle ID is correct.

GOOGLE_APP_ID and the other Firebase configuration values are correct.

The correct GoogleService-Info.plist is present under the MDU/DDU configuration folders.

I have added it as a BundleResource as suggested.

Firebase Analytics is working and I can see active users in Firebase.

But Crashlytics is not working.

I also previously tried the following configuration because of the iOS Release/Crashlytics symbol issue:

<PropertyGroup Condition="$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)')) == 'ios'">
    <_ExportSymbolsExplicitly>false</_ExportSymbolsExplicitly>
</PropertyGroup>

<ItemGroup Condition="$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)')) == 'ios'">
    <_ReferencesLinkerFlags Include="-u __mh_execute_header" />
</ItemGroup>

With this configuration, the application was crashing on startup, so I removed it and changed it to:

<ItemGroup Condition="$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)')) == 'ios'">
    <ReferenceNativeSymbol Include="_mh_execute_header" SymbolType="Function" />
</ItemGroup>

After this change, the application launches, but I am now getting the GoogleService-Info.plist exception above.

Could you please help me understand why Firebase Analytics is working but FirebaseApp.configure() is saying that it cannot find the GoogleService-Info.plist?

Is there any additional configuration required for .NET 10 MAUI iOS when using different GoogleService-Info.plist files for multiple configurations?

Thanks.