Android app restarts on orientation change

My app contains fragments, and it's mainly a fragment application. I have only 3 activities, others are all fragments. But from any point of the app when I rotate the phone in landscape mode or portrait the application restarts and continues from the Start Point of the app, from the beginning. I put the android:configChanges="orientation|keyboardHidden|keyboard" in the Manifest, but it seems it has no effect at all. I'm populating the fragments only with one web view. But I also change the actionbar color. That's all I do in the app. It's a static app, there is no user input. Here's a sample code of how my fragments look like:

public class CLASSNAME extends Fragment {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    this.setRetainInstance(true);
}

@Override
public View onCreateView(final LayoutInflater inflater, final ViewGroup container, Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.LAYOUT, container, false);
    ActionBar bar = getActivity().getActionBar();
    bar.setBackgroundDrawable(new ColorDrawable(getResources().getColor(R.color.COLOR)));
    bar.setTitle("TITLE");


    final WebView wFirst = (WebView) view.findViewById(R.id.WEBVIEWID);
    wFirst.getSettings().setJavaScriptEnabled(true);
    wFirst.setBackgroundColor(0x00000000);

    wFirst.loadDataWithBaseURL(LOADING DATA);
    wFirst.setWebViewClient(new WebViewClient() {SETTING UP WEBVIEW CLIENT});

return view;
}
}

I read lots of posts that got answered with Save Instance State and those other methods, but in my case I have no idea what to save and how to keep my activity rolling even if the orientation is changed.

This is the MainActivity.class code:

public class MainActivity extends Activity
        implements NavigationDrawerFragment.NavigationDrawerCallbacks {

    /**
     * Fragment managing the behaviors, interactions and presentation of the navigation drawer.
     */
    private NavigationDrawerFragment mNavigationDrawerFragment;

    private static CharSequence mTitle;
    public static Context context;

    public static Context getContext() {
        return context;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        context = getApplicationContext();

        mNavigationDrawerFragment = (NavigationDrawerFragment)
                getFragmentManager().findFragmentById(R.id.navigation_drawer);
        mTitle = getTitle();

        // Set up the drawer.
        mNavigationDrawerFragment.setUp(
                R.id.navigation_drawer,
                (DrawerLayout) findViewById(R.id.drawer_layout));
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        android.os.Process.killProcess(android.os.Process.myPid());
        super.onDestroy();
    }

    @Override
    public void onBackPressed() {
        super.onBackPressed();
        finish();
    }

    @Override
    public void onNavigationDrawerItemSelected(int position) {
        // update the main content by replacing fragments
        FragmentManager fragmentManager = getFragmentManager();

        switch (position) {
            case 1:
                fragmentManager.beginTransaction()
                        .replace(R.id.container, new AlgebraicGraphs())
                        .commit();
                break;
            case 2:
                fragmentManager.beginTransaction()
                        .replace(R.id.container, new Logarithms())
                        .commit();
                break;
            case 3:
                fragmentManager.beginTransaction()
                        .replace(R.id.container, new Polynomials())
                        .commit();
                break;
            case 4:
                fragmentManager.beginTransaction()
                        .replace(R.id.container, new Powers())
                        .commit();
                break;
            case 6:
                fragmentManager.beginTransaction()
                        .replace(R.id.container, new AreaFormulas())
                        .commit();
                break;
            case 7:
                fragmentManager.beginTransaction()
                        .replace(R.id.container, new SurfaceAreaFormulas())
                        .commit();
                break;
            case 8:
                fragmentManager.beginTransaction()
                        .replace(R.id.container, new PerimeterFormulas())
                        .commit();
                break;
            case 9:
                fragmentManager.beginTransaction()
                        .replace(R.id.container, new VolumeFormulas())
                        .commit();
                break;
            case 11:
                fragmentManager.beginTransaction()
                        .replace(R.id.container, new TrigonometryGraphsFormulas())
                        .commit();
                break;
            case 12:
                fragmentManager.beginTransaction()
                        .replace(R.id.container, new HyperbolicIdentities())
                        .commit();
                break;
            case 13:
                fragmentManager.beginTransaction()
                        .replace(R.id.container, new TrigonometricIdentities())
                        .commit();
                break;
            case 16:
                fragmentManager.beginTransaction()
                        .replace(R.id.container, new IntegralIdentities())
                        .commit();
                break;
            case 17:
                fragmentManager.beginTransaction()
                        .replace(R.id.container, new IntegralSpecialFunctions())
                        .commit();
                break;
            case 18:
                fragmentManager.beginTransaction()
                        .replace(R.id.container, new TableOfIntegrals())
                        .commit();
                break;
            case 20:
                fragmentManager.beginTransaction()
                        .replace(R.id.container, new DerivativeIdentities())
                        .commit();
                break;
            case 21:
                fragmentManager.beginTransaction()
                        .replace(R.id.container, new TableOfDerivatives())
                        .commit();
                break;
            default:
                fragmentManager.beginTransaction()
                        .replace(R.id.container, new DefaultLayout())
                        .commit();
                break;
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        if (!mNavigationDrawerFragment.isDrawerOpen()) {
            // Only show items in the action bar relevant to this screen
            // if the drawer is not showing. Otherwise, let the drawer
            // decide what to show in the action bar.
            getMenuInflater().inflate(R.menu.main, menu);
            return true;
        }
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();
        if (id == R.id.action_about) {
            About about = new About();
            about.show(getFragmentManager(), "about");
        }
        return false;
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {
        /**
         * The fragment argument representing the section number for this
         * fragment.
         */
        private static final String ARG_SECTION_NUMBER = "section_number";

        /**
         * Returns a new instance of this fragment for the given section
         * number.
         */
        public static PlaceholderFragment newInstance(int sectionNumber) {
            PlaceholderFragment fragment = new PlaceholderFragment();
            Bundle args = new Bundle();
            args.putInt(ARG_SECTION_NUMBER, sectionNumber);
            fragment.setArguments(args);
            return fragment;
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main, container, false);
            return rootView;
        }
    }
}

This is the log:

02-19 06:41:24.849    9788-9788/l.pocketformulas E/AndroidRuntime﹕ FATAL EXCEPTION: main
    java.lang.IllegalStateException: Fragment Logarithms{4132f5d0} not attached to Activity
            at android.app.Fragment.getResources(Fragment.java:828)
            at l.pocketformulas.Logarithms$1.onPageFinished(Logarithms.java:71)
            at android.webkit.CallbackProxy.handleMessage(CallbackProxy.java:444)
            at android.os.Handler.dispatchMessage(Handler.java:99)
            at android.os.Looper.loop(Looper.java:155)
            at android.app.ActivityThread.main(ActivityThread.java:5520)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:511)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1029)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:796)
            at dalvik.system.NativeStart.main(Native Method)

Use this in you AndroidMenifest.xml

<activity
            android:name="MyActivity"
            android:configChanges="orientation|keyboard|keyboardHidden"
            android:screenOrientation="sensor" />

Android restarts the activities whenever the orientation change by default.

You will need to save your data/state by calling onSaveInstanceState() before Android destroys the activities.

Have a look here: Handling Runtime Changes

You could prevent this by adding android:configChanges="orientation" to your activity in AndroidManifest file.

Updates:

When a config change occurs the old Fragment isn't destroyed -- it adds itself back to the Activity when it's recreated. You can stop errors occurring by using the same Fragment rather than recreating a new one. Simply add this code:

if(savedInstanceState == null) 
{
    mFragmentManager = getFragmentManager(); // **update**
    FragmentTransaction ft= mFragmentManager.beginTransaction();

    MyFragment fragment = new MyFragment();

    ft.add(R.id.container, fragment);
    ft.commit();
}

Be warned though: problems will occur if you try and access Activity Views from inside the Fragment as the lifecycles will subtly change. (Getting Views from a parent Activity from a Fragment isn't easy).