How to create an animated button (boobool's Android crash)

package net.dermetfan.someLibgdxTests.screens;

import net.dermetfan.libgdx.graphics.AnimatedSprite;
import net.dermetfan.someLibgdxTests.SomeLibgdxTests;

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.Screen;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.Animation;
import com.badlogic.gdx.graphics.g2d.BitmapFont;
import com.badlogic.gdx.graphics.g2d.TextureRegion;
import com.badlogic.gdx.scenes.scene2d.InputEvent;
import com.badlogic.gdx.scenes.scene2d.Stage;
import com.badlogic.gdx.scenes.scene2d.ui.TextButton;
import com.badlogic.gdx.scenes.scene2d.ui.TextButton.TextButtonStyle;
import com.badlogic.gdx.scenes.scene2d.utils.ClickListener;
import com.badlogic.gdx.scenes.scene2d.utils.SpriteDrawable;

public class AnimatedButtonTest implements Screen {

    private Stage stage;

    @Override
    public void render(float delta) {
        Gdx.gl.glClearColor(0, 0, 0, 1);
        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

        stage.act(delta);
        stage.draw();
    }

    @Override
    public void resize(int width, int height) {
    }

    @Override
    public void show() {
        stage = new Stage();

        Gdx.input.setInputProcessor(stage);

        // create the animation for the AnimatedSprite
        Animation animation = new Animation(1 / 3f, new TextureRegion(new Texture("img/1.png")), new TextureRegion(new Texture("img/2.png")), new TextureRegion(new Texture("img/3.png"));
        animation.setPlayMode(Animation.LOOP);

        // create the AnimatedSprite and set its keepSize to true
        AnimatedSprite animatedSprite = new AnimatedSprite(animation);
        animatedSprite.setKeepSize(true);

        // create the TextButtonStyle for the TextButton and set the up Drawable to a SpriteDrawable to pass the AnimatedSprite in
        TextButtonStyle tbs = new TextButtonStyle();
        tbs.font = new BitmapFont();
        tbs.up = new SpriteDrawable(animatedSprite);

        TextButton button = new TextButton("TEST", tbs);
        // add some test listener to the button
        button.addListener(new ClickListener() {
            @Override
            public void clicked(InputEvent event, float x, float y) {
                System.out.println("clicked");
            }
        });

        stage.addActor(button);
    }

    @Override
    public void hide() {
        dispose();
    }

    @Override
    public void pause() {
    }

    @Override
    public void resume() {
    }

    @Override
    public void dispose() {
        stage.dispose();
    }

}