Interstitial Admob Doesn't Work : AFMA_ReceiveMessage Is Not Defined

I have two kind of ads : banner and interstitial. The first one works very well, but when I want to display an interstitial ad when I pressed the back button (but we don't care of

Solution 1:

My code use to add InterstitialAdd:

public static void addInterstitialAd(final Activity context, final int id) {
    final InterstitialAd interstitial = new InterstitialAd(context);
    interstitial.setAdUnitId(context.getString(id));
    interstitial.loadAd(new AdRequest.Builder().build());
    interstitial.setAdListener(new AdListener() {
        @Override
        public void onAdLoaded() {
            // Call displayInterstitial() function
            if (interstitial.isLoaded()) {
                interstitial.show();
            }
        }
    });
}

You can try it if not work, please separate to new thread:

 new Thread(new Runnable() {
        public void run() {
        final InterstitialAd interstitial = new InterstitialAd(context);
        interstitial.setAdUnitId(context.getString(id));
        interstitial.loadAd(new AdRequest.Builder().build());
        interstitial.setAdListener(new AdListener() {
            @Override
            public void onAdLoaded() {
                // Call displayInterstitial() function
                if (interstitial.isLoaded()) {
                runOnUiThread(new Runnable() {
                public void run() {
                    interstitial.show();
                }
              });                
             }
            }
        });
     }
    }).start();

If your want after click back -> Admod-> close admod -> apclose:

@Override
    public void onBackPressed() {
        final InterstitialAd interstitial = new InterstitialAd(getApplicationContext());
        interstitial.setAdUnitId(getApplicationContext().getString(id));
        interstitial.loadAd(new AdRequest.Builder().build());
        interstitial.setAdListener(new AdListener() {
            @Override
            public void onAdLoaded() {
                // Call displayInterstitial() function
                if (interstitial.isLoaded()) {
                    interstitial.show();
                }
            }
            @Override
            public void onAdClosed(){
                finish();
            }
            @Override
            public void onAdFailedToLoad(int errorCode){
                //you can implement continue load or finish 
            }

        });
    }

Solution 2:

Do not place interstitial ads on app load and when exiting apps as interstitials should only be placed in between pages of app content.