title: Ad request successful, but no ad returned due to lack of ad inventory
body: <p>I new in AdMob. At first I'm trying to create a test app with different types of ad.
  I use real ad_unit_id and nexus 4 for testing.</p>
  
  <p>I use 1 layout xml for all activity:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:ads="http://schemas.android.com/apk/lib/com.google.ads"
      android:id="@+id/empty_layout"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:orientation="vertical" &gt;
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>When i create simple activity with banner ad it's work fine. Activity code:</p>
  
  <pre><code>public class AdBannerActivity extends Activity {
  
      private AdView adView;
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.ad_empty);
  
          adView = new AdView(this, AdSize.SMART_BANNER, getString(R.string.adUnitId));
          adView.setAdListener(this);
  
          LinearLayout layout = (LinearLayout) findViewById(R.id.empty_layout);
  
          layout.addView(adView);
  
          adView.loadAd(new AdRequest());
      }
  
      @Override
      public void onDestroy() {
          if (adView != null) {
              adView.destroy();
          }
          super.onDestroy();
      }
  }
  </code></pre>
  
  <p>When i try to create activity with full screen ad, i have error message:</p>
  
  <pre><code>Ad request successful, but no ad returned due to lack of ad inventory.
  </code></pre>
  
  <p>Activity code:</p>
  
  <pre><code>public class AdInterstitialActivity extends Activity implements AdListener {
  
      private InterstitialAd interstitial;
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.ad_empty);
  
          interstitial = new InterstitialAd(this, getString(R.string.adUnitId));
  
          interstitial.setAdListener(this);
  
          AdRequest adRequest = new AdRequest();
  
          interstitial.loadAd(adRequest);
      }
  
      @Override
      public void onReceiveAd(Ad ad) {
          if (ad == interstitial) {
              interstitial.show();
          }
      }
  
      @Override
      public void onDismissScreen(Ad ad) {
      }
  
      @Override
      public void onFailedToReceiveAd(Ad ad, ErrorCode error) {
          Log.e("AdTest", "Error code: " + error);
      }
  
      @Override
      public void onLeaveApplication(Ad ad) {
      }
  
      @Override
      public void onPresentScreen(Ad ad) {
      }
  }
  </code></pre>
  
  <p>What am I doing wrong?
  How to solve this problem?</p>
  
  <p><strong>Solution:</strong> Create new ad_unit_id for interstitial ads in AdMob account.</p>