不需要的纹理渲染

Question

目前我正在使用libgdx 1.4.1在我的游戏的各个点都有不需要的纹理问题，我正在分享一个这样的问题的屏幕截图（黑色字符带有弹出退出）。在游戏中，我有彩色字符的纹理图集（spritesheet）而不是这些黑色字符。

发生的条件：

1. On ads loading(banner/interstitial admob ads).
2. In app purchase.
3. sometime on google leaderboard.
4. On resume after home button press(rarely).
5. On resume in case of exit (sometime if i commented assetmannage.dispose()).

问题。

1.Random texture any where.
2.black fonts/texture after resume

我的代码实现。 我正在使用assest manager类来加载所有纹理。

public void create() {    
    FileHandleResolver resolver=new InternalFileHandleResolver();
    assetManager = new AssetManager(resolver);
    Texture.setAssetManager(assetManager);
    assetManager.setLoader(FreeTypeFontGenerator.class, new FreeTypeFontGeneratorLoader(resolver));
    assetManager.setLoader(BitmapFont.class, ".ttf", new FreetypeFontLoader(resolver));

    Texture.setAssetManager(assetManager);
    //loading fonts.............
    for (int i = 1; i < 3; i++) {
        int size=9*(1+i);
        FreeTypeFontLoaderParameter fontParameterS=new FreeTypeFontLoaderParameter();
        fontParameterS.fontFileName=Constants._strungFontPath;
        fontParameterS.fontParameters.size=size;
        fontParameterS.fontParameters.characters="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890\"!`?'.,;:|/@\\^$-%+=#_&";
        assetManager.load("stungFont"+size+".ttf",BitmapFont.class,fontParameterS);
    }   
}   

public void loadingResourceDuringSplash() {
    //Loading some CSV,s
    Pixmap pixmap=new Pixmap(20,20, Format.RGBA4444);
    pixmap.setColor(1, 1, 1,1);
    pixmap.fill();
    blankTexture=new Texture(pixmap);
    // pixmap.dispose();    
    loadAssetsINAssetManager();
}    

private void loadAssetsINAssetManager() {
    assetManager.load("img/Moles.atlas", TextureAtlas.class);   
    assetManager.load("img/tutorial.atlas", TextureAtlas.class);
    assetManager.load("img/Main_BG.png", Texture.class);    
    assetManager.load("img/tree.png", Texture.class);
    //some other file texture to..
}
public void render() {
    super.render();
    assetManager.update();
    sleep();
}

@Override
public void dispose() {
    super.dispose();
    //  assetManager.dispose();  // makes problem less frequent 
    //  blankTexture.dispose();
    //  pointTexture.dispose();
}

@Override
public void resume() {
    super.resume();
    Texture.setAssetManager(assetManager);
    loadAssetsINAssetManager();
    assetManager.finishLoading();    
}