Fragment already added IllegalStateException

If the state of the activity has already been saved its no longer safe to call commit. You must call commitAllowingStateLoss() instead. Hope this helps!

Edit: ok I've taken a closer look at your issue, problem is you are trying to add a fragment that has already been added. Even if you use replace or remove calls you can't do this. Only work around I have found is to create a new instance of a fragment and add it every time. Once you remove or replace a fragment it is best to drop all of your references to it so the GC can take care of it.

Probably not related to this issue directly, but I've also noticed that setting a transition to the FragmentTransaction will cause an IllegalStateException, while not setting a transition will not.

Here's the bug for this issue: http://code.google.com/p/android/issues/detail?id=25598

In the end my workaround was to execute remove() of the previous fragment and add() the new one. Although that's what replace() method was meant to do.

But I am still guessing why replace() method didn't work properly in this case. It is really weird and I want to discard that it is because I am misunderstanding something or doing something wrong.

I used this:

if (getFragmentManager().findFragmentByTag(newFragment.getClass().getName()) != null) {
   transaction.remove(newFragment);
 }

and added fragment with

MyFragment frag = new MyFragment(); 
transaction.add(R.id.container, frag, MyFragment.class.getName())

MyFragment.class.getName() stands for tag