Видео с вознаграждением Не загружается с сервера объявлений. Не удалось загрузить? Android

Я пытаюсь внедрить рекламу admob во фрагменте, но прошел месяц, а я все еще получаю ошибку 3 (нет объявлений для заполнения).

Я пробовал использовать новый идентификатор, но все равно получаю ту же ошибку, тестовые объявления работают нормально. logcat:

    08-03 16:59:21.653 9892-10265/? W/AdvertisingIdClient: Error while reading from SharedPreferences
    java.lang.SecurityException: MODE_WORLD_READABLE no longer supported
    at android.app.ContextImpl.checkMode(ContextImpl.java:2134)
    at android.app.ContextImpl.getSharedPreferences(ContextImpl.java:354)
    at android.app.ContextImpl.getSharedPreferences(ContextImpl.java:349)
    at 
 com.google.android.gms.ads.identifier.AdvertisingIdClient.getAdvertisingIdInfo(Unknown Source)
    at com.duapps.ad.base.GoogleAdvertisingIdHelper.getAdIdNormal(GoogleAdvertisingIdHelper.java:46)
        at com.duapps.ad.base.GoogleAdvertisingIdHelper.getAdId(GoogleAdvertisingIdHelper.java:33)
        at com.duapps.ad.base.HttpParamsHelper.commonParams(HttpParamsHelper.java:118)
        at com.duapps.ad.stats.ToolStatsCore.pushToServer(ToolStatsCore.java:370)
        at com.duapps.ad.stats.ToolStatsCore.report(ToolStatsCore.java:325)
        at com.duapps.ad.stats.ToolStatsCore.handleMessage(ToolStatsCore.java:217)
        at android.os.Handler.dispatchMessage(Handler.java:98)
        at android.os.Looper.loop(Looper.java:154)
        at android.os.HandlerThread.run(HandlerThread.java:61)
        08-03 16:59:24.873 26224-26246/? D/DynamitePackage: Instantiating 
        com.google.android.gms.ads.adshield.ChimeraAdShieldCreatorImpl
        08-03 16:59:25.489 25315-25315/com.nsdeveloper.apppromotion I/Ads: 
        Starting ad request.
        08-03 16:59:25.489 25315-25315/com.nsdeveloper.apppromotion I/Ads: Use 
       AdRequest.Builder.addTestDevice("10C9D896CF812C194BD949D82F766C9B") 
        to get test ads on this device.
        08-03 16:59:25.850 25315-25332/com.nsdeveloper.apppromotion I/Ads: No fill from ad server.
        08-03 16:59:25.850 25315-25315/com.nsdeveloper.apppromotion W/Ads: Failed to load ad: 3

Я реализую рекламу во фрагменте, поэтому в контексте я передавал getActivity ():

MobileAds.initialize(getActivity(), "xxxxxxxxxxxxxxxxxxx");
mRewardedVideoAd = MobileAds.getRewardedVideoAdInstance(getActivity());
    mRewardedVideoAd.setRewardedVideoAdListener(rewardAdListener);
    loadRewardedAdVideo();

RewardVideoAdListener

RewardedVideoAdListener rewardAdListener = new RewardedVideoAdListener() {

    @Override
    public void onRewardedVideoAdLoaded() {
        Toast.makeText(getActivity(),"ad is loaded",Toast.LENGTH_SHORT).show();
        Log.d("ADS_SHOW","loaded");


    }

    @Override
    public void onRewardedVideoAdOpened() {

    }

    @Override
    public void onRewardedVideoStarted() {

    }

    @Override
    public void onRewardedVideoAdClosed() {
        loadRewardedAdVideo();
    }

    @Override
    public void onRewarded(RewardItem rewardItem) {
        int rewardPoints =   rewardItem.getAmount();
        int userPoints = getActivity().getSharedPreferences(PREFERENCE,0).getInt(POINTS,0) - rewardPoints;
        userRef.child(POINTS).setValue(userPoints);
        getActivity().getSharedPreferences(PREFERENCE,0).edit().putInt(POINTS,userPoints).commit();




    }

    @Override
    public void onRewardedVideoAdLeftApplication() {

    }

    @Override
    public void onRewardedVideoAdFailedToLoad(int i) {
        Toast.makeText(getActivity(),"No ads to show "+i,Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onRewardedVideoCompleted() {





    }
};


private void loadRewardedAdVideo(){
    if (! mRewardedVideoAd.isLoaded()){
         mRewardedVideoAd.loadAd("ca-app-pub-xxxxxxxxx", new AdRequest.Builder().build());
    }
}