ADMOB: The following classes could not be instantiated: - com.google.android.gms.ads.AdView

Question

I updated my opld admob to the new admob. I downloaded SDK, imported google play service library and done everything in google documantation. But when I add the xml code:

<com.google.android.gms.ads.AdView android:id="@+id/adView"
                     android:layout_width="wrap_content"
                     android:layout_height="wrap_content"
                     ads:adUnitId="ca-app-pub-111111111111111/1111111"
                     ads:adSize="BANNER"/>

I get the following message in error log:

The following classes could not be instantiated: - com.google.android.gms.ads.AdView

EDIT: There is Manifest XML code:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.testapp"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="21" />

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <meta-data android:name="com.google.android.gms.version"
           android:value="@integer/google_play_services_version"/>

    <activity
        android:name=".MainActivity"
        android:label="@string/app_name" >
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity android:name="com.google.android.gms.ads.AdActivity"
         android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize"/>       
</application>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

Coul you help me please?

Answer 1

Make sure you use the right ad namespace in your layout. You should use : xmlns:ads="http://schemas.android.com/apk/res-auto"

So change:

 <com.google.ads.AdView
        xmlns:ads="http://schemas.android.com/apk/lib/com.google.ads"
        android:id="@+id/adView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        ads:adUnitId="MY_AD_UNIT_ID"
        ads:adSize="BANNER"
        ads:testDevices="TEST_EMULATOR, TEST_DEVICE_ID"
        ads:loadAdOnCreate="true"/>

To:

<com.google.android.gms.ads.AdView
    xmlns:ads="http://schemas.android.com/apk/res-auto"
    android:id="@+id/adView"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    ads:adUnitId="MY_AD_UNIT_ID"
    ads:adSize="BANNER"/>