Java – Class Not Found Exception : Didn’t find class “com.google.android.gms.ads.AdView”

I’ve done a lot of research and it seems to be a common mistake for many users, but the reasons vary. I found none of them worked for me.

I got it

java.lang.RuntimeException: Unable to start activity ComponentInfo{
[...] /[...]. activities. StartActivity}: android.view.InflateException:
Binary XML file line #173: Error inflating class [...]. BannerAd
    [...]
Caused by: android.view.InflateException: Binary XML file line #8: Error
inflating class com.google.android.gms.ads.AdView
    [...]
Caused by: java.lang.ClassNotFoundException: Didn't find class
"com.google.android.gms.ads.AdView" on path: DexPathList[[zip file
"/data/app/[...] -1.apk"],nativeLibraryDirectories=[/data/app-lib/[...] -1,
/vendor/lib, /system/lib]]

I’m installing the latest version of ADT and SDK packages. I copied google-play-services_lib to my workspace and imported it as an Android project. I added it as a library to my app project. I checked everything under “Order & Export”.

I have a banner_ad.xml:

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal|top"
    android:orientation="vertical" >

<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:adSize="BANNER"
        ads:adUnitId="[...]" />

</LinearLayout>

And the BannerAd.java I’m using:

package [...];

import android.content.Context;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.widget.LinearLayout;

import [...]. R;
import [...]. general. Settings;
import com.google.android.gms.ads.AdRequest;
import com.google.android.gms.ads.AdView;

public class BannerAd extends LinearLayout {
    public BannerAd(Context context, AttributeSet attrs) {
        super(context, attrs);

if (!Settings.PRO) {
            LayoutInflater mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            mInflater.inflate(R.layout.banner_ad, this, true);

AdView adView = (AdView) this.findViewById(R.id.adView);
            AdRequest adRequest = new AdRequest.Builder().build();
            adView.loadAd(adRequest);
        }
    }
}

Could it be related to Proguard? I don’t know, this is my proguard-project.txt file, but :

# To enable ProGuard in your project, edit project.properties
# to define the proguard.config property as described in that file.
#
# Add project specific ProGuard rules here.
# By default, the flags in this file are appended to flags specified
# in ${sdk.dir}/tools/proguard/proguard-android.txt
# You can edit the include path and order by changing the ProGuard
# include property in project.properties.
#
# For more details, see
#   http://developer.android.com/guide/developing/tools/proguard.html

# Add any project specific keep options here:

# If your project uses WebView with JS, uncomment the following
# and specify the fully qualified class name to the JavaScript interface
# class:
#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
#   public *;
#}

-keep class * extends java.util.ListResourceBundle {
    protected Object[][] getContents();
}

-keep public class com.google.android.gms.common.internal.safeparcel.SafeParcelable {
    public static final *** NULL;
}

-keepnames @com.google.android.gms.common.annotation.KeepName class *
-keepclassmembernames class * {
    @com.google.android.gms.common.annotation.KeepName *;
}

-keepnames class * implements android.os.Parcelable {
    public static final ** CREATOR;
}

Any ideas to fix this?

EDIT: Sometimes, I also get output like this in the console (but not every compilation, just sometimes):

[2014-07-24 12:49:05 - [...]] Dx 
trouble processing:
[2014-07-24 12:49:05 - [...]] Dx bad class file magic (cafebabe) or version (0033.0000)
... while parsing com/google/android/gms/internal/mb.class
... while processing com/google/android/gms/internal/mb.class
[2014-07-24 12:49:05 - [...]] Dx 
trouble processing:
[2014-07-24 12:49:05 - [...]] Dx bad class file magic (cafebabe) or version (0033.0000)
... while parsing com/google/android/gms/internal/mc.class
... while processing com/google/android/gms/internal/mc.class
[2014-07-24 12:49:05 - [...]] Dx 
[...]
[Lots of similar warnings here]
[...]
trouble processing:
[2014-07-24 12:49:25 - [...]] Dx bad class file magic (cafebabe) or version (0033.0000)
... while parsing com/google/ads/mediation/customevent/CustomEventAdapter$a.class
... while processing com/google/ads/mediation/customevent/CustomEventAdapter$a.class
[2014-07-24 12:49:25 - [...]] Dx 
trouble processing:
[2014-07-24 12:49:25 - [...]] Dx bad class file magic (cafebabe) or version (0033.0000)
... while parsing com/google/ads/mediation/customevent/CustomEventServerParameters.class
... while processing com/google/ads/mediation/customevent/CustomEventServerParameters.class
[2014-07-24 12:49:25 - [...]] Dx 2786 warnings

This is because of ProGuard. To safely use ProGuard with Google Mobile Ads, add the following to your ProGuard configuration:

-keep public class com.google.android.gms.ads.** {
   public *;
}

-keep public class com.google.ads.** {
   public *;
}