Getting Invalid application ID error when using Test application ID with adMob

Question

I am getting an error when i am trying to implement admob to my app:

java.lang.RuntimeException: Unable to get provider com.google.android.gms.ads.MobileAdsInitProvider: java.lang.IllegalStateException:Invalid application ID

I am using test application ID. Here is my manifest:

<meta-data 
android:name="com.google.android.gms.ads.APPLICATION_ID"
android:value="ca-app-pub-3940256099942544/6300978111"/>

Gradle:

implementation 'com.google.android.gms:play-services-ads:18.1.1'

Activity code

MobileAds.initialize(this, new OnInitializationCompleteListener() {
            @Override
            public void onInitializationComplete(InitializationStatus initializationStatus) {
            }
        });

        mAdView = findViewById(R.id.adView);
        AdRequest adRequest = new AdRequest.Builder().addTestDevice(AdRequest.DEVICE_ID_EMULATOR).build();
        mAdView.loadAd(adRequest);

XML code

xmlns:ads="http://schemas.android.com/apk/res-auto"
        android:id="@+id/adView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_centerHorizontal="true"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginBottom="8dp"
        ads:adSize="BANNER"
        ads:adUnitId="ca-app-pub-3940256099942544/6300978111"

I do not understand why i am still getting Invalid application ID code. I am using test application ID

Answer 1

You put your Ad Unit ID in AndroidManifest.xml - which is wrong. You should add your AdMob App ID here.

Ad Unit IDs have this format:

ca-app-pub-3940256099942544/6300978111  //Test ID for a banner

AdMob App IDs have this format:

ca-app-pub-3940256099942544~3347511713  //Test App ID