EmptyStackException

[Fanom2813]

Hello guys, i have this problem where by sometimes if i leave the app for a moment and it goes to sleep then i try navigate through the app i get this error :

java.util.EmptyStackException
at com.smartcabspro.user.MainActivity.onBackPressed(:4)

what could be the problem ?

[MertNYuksel]

This seems weird. What is your onBackPressed function look like? Do you use navigator.canGoBack function just like in samples? If you do, can you send us a sample that reproduce this crash?
https://github.com/Trendyol/medusa/wiki/Basic-Usage

[Fanom2813]

i have followed the exact same thing as the tutorial

MultipleStackNavigator multipleStackNavigator;
    private List<Function0<Fragment>> rootsFragmentProvider = Arrays
            .asList(
                    new Function0<Fragment>() {
                        @Override
                        public Fragment invoke() {
                            return new HomeFragment();
                        }
                    },
...

@Override
   protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState)

       multipleStackNavigator = new MultipleStackNavigator(
               getSupportFragmentManager(),
               R.id.fragment_host,
               rootsFragmentProvider,
               this,
               new NavigatorConfiguration(0, true, NavigatorTransaction.ATTACH_DETACH),
               null);

       multipleStackNavigator.initialize(savedInstanceState);

@Override
    public void onBackPressed() {
        if (multipleStackNavigator.canGoBack()) {
            multipleStackNavigator.goBack();
        } else {
            super.onBackPressed();
        }
    }

this error happens to me if i let the phone go to sleep mode when the app is running , then after sometime i start using the app again

[MertNYuksel]

It feels like this might related to activity recreation. Did you also override onSaveInstanceState and call navigator.onSaveInstanceState in it?