iOS Crashlytics - NullReferenceException - Object reference not set to an instance of an object.

[richaplinvs]

I am getting an exception accessing any of the Crashlytics methods on iOS. I am also using Analytics too but that is working ok.

The exceptions take the following form:

NullReferenceException - Object reference not set to an instance of an object. 
  at Plugin.Firebase.Crashlytics.FirebaseCrashlyticsImplementation.Log(String message)

NullReferenceException - Object reference not set to an instance of an object.
  at Plugin.Firebase.Crashlytics.FirebaseCrashlyticsImplementation.DidCrashOnPreviousExecution()

I've had quite a few issues inconsistent build and runtime errors integrating Crashlytics. I ran into the issue with the ObjCRuntime.__Registrar__ but uses the static registrar workaround. I tried the latest dotnet (9.0.200) as this should have fixed the underlying issue and avoided the workaround but it didn't.

I call the Crashlytics methods from a test page in the app so the CrossFirebase.Initialize() will have been called.

Here's the relevant content from my csproj

<!-- https://github.com/TobiasBuchholz/Plugin.Firebase/issues/372 that should no longer be needed with newer dotnet
	but still wasn't working with 9.0.200 -->
	<Target Name="SelectStaticRegistrar" AfterTargets="SelectRegistrar">
		<PropertyGroup Condition="'$(Registrar)' == 'managed-static'">
			<Registrar>static</Registrar>
		</PropertyGroup>
	</Target>

	<ItemGroup>
		<PackageReference Include="Plugin.Firebase" Version="3.1.3" />
	</ItemGroup>

	<PropertyGroup Condition="$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)')) == 'ios'">
		<!--https://github.com/xamarin/GoogleApisForiOSComponents/issues/643#issuecomment-1920970044-->
		<_ExportSymbolsExplicitly>false</_ExportSymbolsExplicitly> 
	</PropertyGroup>
	<ItemGroup Condition="$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)')) == 'ios'">
		<BundleResource Include="Platforms\iOS\GoogleService-Info.plist" LogicalName="GoogleService-Info.plist"/>
	</ItemGroup>

	<ItemGroup Condition="$([MSBuild]::GetTargetPlatformIdentifier('$(TargetFramework)')) == 'android'">
		<GoogleServicesJson Include="Platforms\Android\google-services.json" LogicalName="google-services.json" />
	</ItemGroup>

My init code:

private static MauiAppBuilder RegisterFirebaseServices(this MauiAppBuilder builder)
    {
        builder.ConfigureLifecycleEvents(events => {
#if IOS
            events.AddiOS(iOS => iOS.WillFinishLaunching((_,__) => {
                Console.WriteLine("Registering Firebase for iOS");
                CrossFirebase.Initialize();
                return false;
            }));
#elif ANDROID
            events.AddAndroid(android => android.OnCreate((activity, _) => {
                Console.WriteLine("Registering Firebase for Android");
                CrossFirebase.Initialize(activity);
                
            }));
#endif
        });
        
        builder.Services.AddSingleton(_ => CrossFirebaseAuth.Current);
        return builder;
    }

The specific methods:

Plugin.Firebase.Analytics.CrossFirebaseAnalytics.Current.LogEvent("Page OnAppearing"); //This is ok

//Both fail
Plugin.Firebase.Crashlytics.CrossFirebaseCrashlytics.Current.Log("Page OnAppearing");
Plugin.Firebase.Crashlytics.CrossFirebaseCrashlytics.Current.DidCrashOnPreviousExecution();

Any help would gratefully be received!

[AdamEssenmacher]

Just looking at the plugin code, it looks like you'd experience this if the first call to CrossFirebaseCrashlytics.Current happens before FirebaseCrashlytics.SharedInstance is set:

Plugin.Firebase/src/Crashlytics/Platforms/iOS/FirebaseCrashlyticsImplementation.cs

Line 14 in 63d6fbb

_instance = FirebaseCrashlytics.SharedInstance;

Would you be able to share a minimal repro project?