title: IllegalStateException: <MyFragment> is not currently in the FragmentManager
body: <p>I know it sounds like a duplicate of <a href="https://stackoverflow.com/questions/11296411/fragmentstatepageradapter-illegalstateexception-myfragment-is-not-currently">FragmentStatePagerAdapter  IllegalStateException: &lt;MyFragment&gt; is not currently in the FragmentManager</a>
  but his solution isn't relevant to my case.</p>
  
  <p>I'm getting the following crash very rarely:</p>
  
  <blockquote>
    <p>java.lang.RuntimeException: Unable to pause activity {MyActivity}: </p>
    
    <p>...</p>
    
    <p>Caused by: java.lang.IllegalStateException: Fragment MyFragment
    {40648258 id=0x7f070051} is not currently in the FragmentManager at
    android.support.v4.app.FragmentManagerImpl.putFragment(MT:516) at
    android.support.v4.app.FragmentStatePagerAdapter.saveState(MT:185) at
    android.support.v4.view.ViewPager.onSaveInstanceState(MT:881) </p>
    
    <p>...</p>
    
    <p>at android.view.View.saveHierarchyState(View.java:6238) at
    com.android.internal.policy.impl.PhoneWindow.saveHierarchyState(PhoneWindow.java:1522)
    at android.app.Activity.onSaveInstanceState(Activity.java:1138) at
    android.support.v4.app.FragmentActivity.onSaveInstanceState(MT:480) at
    MyActivity.onSaveInstanceState(MT:336)</p>
  </blockquote>
  
  <p>It seems like this is the weird code I can't understand from <code>FragmentStatePagerAdapter</code>:</p>
  
  <pre><code>for (int i=0; i&lt;mFragments.size(); i++) {
      Fragment f = mFragments.get(i);
      if (f != null) {
          if (state == null) {
              state = new Bundle();
          }
          String key = "f" + i;
          mFragmentManager.putFragment(state, key, f);
      }
  }
  </code></pre>
  
  <p>It looks like the adapter gets my <code>Fragment</code> from <code>mFragments</code> but can't add its state to <code>FragmentManager</code>.</p>
  
  <p>I've couldn't find any way to recreate this on my test devices, only received this from some users.</p>
  
  <p>I'm using support package v4.</p>
  
  <p>Any help?
  Thanks.</p>