java.lang.IllegalStateException: Fragment FragmentDecks{221fd7ab} is not currently in the FragmentManager

[hadifar]

Thanks for your well written tutorial @fnk0

When i work with your code i face a problem , when select a category and then press back button and then rotate screen Or press menu button it throws an exception ( i think it's because cant save state of app so when i comment following line in onSaveInstanceState in MainActivity it doesn't gives me error anymore
//getFragmentManager().putFragment(outState, "activeFragment", activeFragment);

Also this is Error i get

java.lang.IllegalStateException: Fragment FragmentDecks{221fd7ab} is not currently in the FragmentManager
at android.app.FragmentManagerImpl.putFragment(FragmentManager.java:568)
at com.essentialwords.amir.essentialwords.MainActivity.onSaveInstanceState(MainActivity.java:136)
at android.app.Activity.performSaveInstanceState(Activity.java:1297)
at android.app.Instrumentation.callActivityOnSaveInstanceState(Instrumentation.java:1272)
at android.app.ActivityThread.callCallActivityOnSaveInstanceState(ActivityThread.java:3923)
at android.app.ActivityThread.performStopActivityInner(ActivityThread.java:3334)
at android.app.ActivityThread.handleStopActivity(ActivityThread.java:3390)
at android.app.ActivityThread.access$1100(ActivityThread.java:144)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1307)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5221)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)

sorry for my bad English :) and tnx for your tutorial