How Do I Fix “AdMob Not Loading: ErrorCode 0” in My Android Game App?

I recently hit a frustrating wall while integrating AdMob banner ads into my Java based Android game. Everything seemed perfect the setup, the XMLs, the permissions, the dependencies but no matter what I tried, the ads just wouldn’t load.

If you’ve stumbled upon this kind of error:

W/DynamiteModule: Local module descriptor class for com.google.firebase.auth not found.
W/Ads: There was a problem getting an ad response. ErrorCode: 0
W/Ads: Failed to load ad: 0

then you’re in the right place. Let me walk you through how I tackled this, from debugging the issue to implementing a clean, functional AdMob integration with extras like retry logic and interstitial ads thrown in for good measure.

Problem Summary

When I launched the game, I was met with this in Logcat:

W/DynamiteModule: Local module descriptor class for com.google.firebase.auth not found.
W/Ads: There was a problem getting an ad response. ErrorCode: 0
W/Ads: Failed to load ad: 0

At first, I thought something was wrong with Firebase. But as it turns out, the core issue was internal to AdMob’s ad response system, especially in development environments.

Cause of the Error

ErrorCode: 0 (INTERNAL_ERROR)

This means AdMob tried to fetch an ad but failed internally. Based on my research, this usually happens when:

• You’re using a real Ad Unit ID on a test device without proper setup.
• Google Play Services on the device is outdated or not available.
• Your AdMob App ID or Ad Unit ID is incorrectly set or doesn’t match your config.
• Your AdRequest is incomplete or being made too early (before initialization finishes).

Firebase Auth Module Warning

W/DynamiteModule: Local module descriptor class for com.google.firebase.auth not found.

This is more of a warning than a critical error. Unless you’re actively using Firebase Auth (which I wasn’t), it’s not the cause of your ads failing.

Fix & Enhancements

Ensure Google Play Services Is Installed

If you’re running this on an emulator, make sure it has Google APIs and Google Play Services enabled. For physical devices, update Google Play Services via the Play Store.

Use a Test Ad Unit (Absolutely Critical in Dev)

In development, you must use Google’s test ad units or register your device as a test device:

adView.setAdUnitId("ca-app-pub-3940256099942544/6300978111"); // Banner Test Ad Unit

Avoid using real ad units during testing not only can this fail silently, but it can also get your account flagged.

Manage the AdView Lifecycle

I moved all lifecycle methods like resume(), pause(), and destroy() into the activity lifecycle to make sure ads are managed cleanly. This helps prevent memory leaks and loading issues.

Working Final Code

Here’s my cleaned-up, working MainActivity.java with banner ad integration:

public class MainActivity extends BaseGameActivity {
    PApplet fragment;
    private static final String MAIN_FRAGMENT_TAG = "main_fragment";
    private AdView adView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        super.onCreate(savedInstanceState);

        getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

        FrameLayout frame = new FrameLayout(this);
        frame.setId(View.generateViewId());

        if (savedInstanceState == null) {
            fragment = new box_jump();
            FragmentTransaction ft = getFragmentManager().beginTransaction();
            ft.add(frame.getId(), fragment, MAIN_FRAGMENT_TAG).commit();
        } else {
            fragment = (PApplet) getFragmentManager().findFragmentByTag(MAIN_FRAGMENT_TAG);
        }

        MobileAds.initialize(this, initializationStatus -> {});

        adView = new AdView(this);
        adView.setAdUnitId("ca-app-pub-3940256099942544/6300978111");
        adView.setAdSize(AdSize.SMART_BANNER);

        RelativeLayout layout = new RelativeLayout(this);
        layout.addView(frame);

        RelativeLayout.LayoutParams adParams = new RelativeLayout.LayoutParams(
                ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        adParams.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
        layout.addView(adView, adParams);

        setContentView(layout);

        loadBannerAd();
    }

    private void loadBannerAd() {
        AdRequest adRequest = new AdRequest.Builder()
                .addTestDevice(AdRequest.DEVICE_ID_EMULATOR)
                .build();
        adView.loadAd(adRequest);
    }

    @Override
    protected void onResume() {
        super.onResume();
        if (adView != null) adView.resume();
    }

    @Override
    protected void onPause() {
        if (adView != null) adView.pause();
        super.onPause();
    }

    @Override
    protected void onDestroy() {
        if (adView != null) adView.destroy();
        super.onDestroy();
    }
}

Retry Ads on Failure

I added an automatic retry mechanism in case an ad fails:

adView.setAdListener(new AdListener() {
    @Override
    public void onAdFailedToLoad(LoadAdError adError) {
        Log.d("AdMob", "Retrying ad load in 30 seconds...");
        new Handler().postDelayed(() -> loadBannerAd(), 30000);
    }
});

Add an Interstitial Ad for Game Over

Perfect for monetizing key events like game-over screens:

private InterstitialAd interstitialAd;

private void loadInterstitialAd() {
    InterstitialAd.load(this,
            "ca-app-pub-3940256099942544/1033173712",
            new AdRequest.Builder().build(),
            new InterstitialAdLoadCallback() {
                @Override
                public void onAdLoaded(@NonNull InterstitialAd ad) {
                    interstitialAd = ad;
                }
                @Override
                public void onAdFailedToLoad(@NonNull LoadAdError adError) {
                    interstitialAd = null;
                }
            });
}

public void showInterstitial() {
    if (interstitialAd != null) {
        interstitialAd.show(this);
    }
}

Build Gradle Setup

Ensure you’ve added these dependencies:

dependencies {
    implementation 'com.google.android.gms:play-services-ads:22.6.0'
    implementation 'com.google.firebase:firebase-core:21.1.1'
    // Only needed if you're using Firebase Auth
    implementation 'com.google.firebase:firebase-auth:22.3.0'
}

Final Tips

• Use test IDs during development always.
• Log everything with Log.d() for easy debugging.
• Make sure Google Play Services is available and up to date.
• Clean and rebuild your project if things seem off.

Final Thoughts

What felt like a small integration turned into a rabbit hole of internal errors, confusing logs, and inconsistent results. But now that I’ve got a fully working setup with banner and interstitial ads and retry logic it’s a solid foundation for monetizing the game without compromising performance.