Android FragmentTabHost : No tab known for tag null

This is the code that I’ve used to initialise the TabHost and it works fine:

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentTabHost;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class DetailFragment extends Fragment {

    /**
     * Mandatory empty constructor for the fragment manager to instantiate the fragment (e.g. upon screen orientation changes).
     */
    public DetailFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        // R.layout.fragment_tabs_pager contains the layout as specified in your question
        View rootView = inflater.inflate(R.layout.fragment_tabs_pager, container, false);

        // Initialise the tab-host
        FragmentTabHost mTabHost = (FragmentTabHost) rootView.findViewById(R.id.tabhost);
        mTabHost.setup(getActivity(), getChildFragmentManager(), R.id.realtabcontent);

        // Initialise this list somewhere with the content that should be displayed
        List<String> itemsToBeDisplayed;

        for (String subItem : itemsToBeDisplayed) {
            // Give along the name - you can use this to hand over an ID for example
            Bundle b = new Bundle();
            b.putString("TAB_ITEM_NAME", subItem);

            // Add a tab to the tabHost
            mTabHost.addTab(mTabHost.newTabSpec(subItem).setIndicator(subItem), YourContentFragment.class, b);
        }
        return rootView;
    }
}

/**
  * This class contains the actual content of a single tab  
  */
public class YourContentFragment extends Fragment {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        Bundle extras = getArguments();
        if (extras != null) {
            if (extras.containsKey("TAB_ITEM_NAME")) {
                String subItem = extras.getString("TAB_ITEM_NAME");
                // Do something with that string
            }
        }
    }
}