Couldn't load asset 'cars2.png, com.badlogic.gdx.graphics.g2d.TextureAtlas',Libgdx
com.badlogic.gdx.utils.GdxRuntimeException: Error reading pack file: cars2.png

import com.badlogic.gdx.Gdx;


public class Constants {
    public static final float VIEWPORT_WIDTH = 9.0F;
    public static final float VIEWPORT_HEIGHT = 16.0F;
    public static final String TEXTURE_ATLAS_OBJECTS = "cars2.png";

}

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.assets.AssetDescriptor;
import com.badlogic.gdx.assets.AssetErrorListener;
import com.badlogic.gdx.assets.AssetManager;
import com.badlogic.gdx.graphics.g2d.TextureAtlas;
import com.badlogic.gdx.utils.Disposable;
import com.badlogic.gdx.graphics.g2d.TextureAtlas.AtlasRegion;
import com.splitspark.roadfightc.Constants;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.Texture.TextureFilter;


public class Assets implements Disposable, AssetErrorListener {
    public static final String TAG = Assets.class.getName();
    public static final Assets instance = new Assets();
    private AssetManager assetManager;
    public AssetMaincar maincar;
    public EnemyCar1 enemyCar1;
    public EnemyCar2 enemyCar2;
    public EnemyCar3 enemyCar3;
    public Truck truck;
    //public AssetLevelDecoration levelDecoration;


    private Assets() {}

    public void init (AssetManager assetManager) {
        this.assetManager = assetManager;
        // set asset manager error handler
        assetManager.setErrorListener(this);
        // load texture atlas
        assetManager.load(Constants.TEXTURE_ATLAS_OBJECTS, TextureAtlas.class);
        //start loading assets and wait until finished
        assetManager.finishLoading();
        Gdx.app.debug(TAG, "# of assets loaded: " + assetManager.getAssetNames().size);
        for (String a : assetManager.getAssetNames())
            Gdx.app.debug(TAG, "asset: " + a);

        TextureAtlas atlas = assetManager.get(Constants.TEXTURE_ATLAS_OBJECTS);

        // enable texture filtering for pixel smoothing

        for (Texture t : atlas.getTextures())
            t.setFilter(TextureFilter.Linear, TextureFilter.Linear);

        // create game resource objects
        maincar = new AssetMaincar(atlas);
        enemyCar1 = new EnemyCar1(atlas);
        enemyCar2 = new EnemyCar2(atlas);
        enemyCar3 = new EnemyCar3(atlas);
        truck = new Truck(atlas);
        //levelDecoration = new AssetLevelDecoration(atlas);
    }
    @Override
    public void dispose () {
        assetManager.dispose();
    }


    @Override
    public void error (AssetDescriptor filename, Throwable throwable) {
        Gdx.app.error(TAG, "Couldn't load asset '"
                + filename + "'", (Exception) throwable);
    }

    public class AssetMaincar {
        public final AtlasRegion car;
        public AssetMaincar (TextureAtlas atlas) {
            car = atlas.findRegion("main_car");
        }
    }

    public class EnemyCar1 {
        public final AtlasRegion encar1;
        public EnemyCar1 (TextureAtlas atlas) {
            encar1 = atlas.findRegion("enemy_car_1");
        }
    }

    public class EnemyCar2 {
        public final AtlasRegion encar2;
        public EnemyCar2 (TextureAtlas atlas) {
            encar2 = atlas.findRegion("enemy_car_2");
        }
    }

    public class EnemyCar3 {
        public final AtlasRegion encar3;
        public EnemyCar3 (TextureAtlas atlas) {
            encar3 = atlas.findRegion("enemy_car_3");
        }
    }

    public class Truck {
        public final AtlasRegion truck;
        public Truck (TextureAtlas atlas) {
            truck = atlas.findRegion("truck");
        }
    }

    public class ManholeOpen {
        public final AtlasRegion manhole;
        public ManholeOpen (TextureAtlas atlas) {
            manhole = atlas.findRegion("manhole");
        }
    }

    public class ManholeClosed {
        public final AtlasRegion manholec;
        public ManholeClosed (TextureAtlas atlas) {
            manholec = atlas.findRegion("manholec");
        }
    }