Estou tentando exibir um mapa em uma das minhas classes de fragmento. Fiz um fragmento na classe XML para o mapa e usei-o assim:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_profile, container, false);
    GoogleMap mapFragment = ((SupportMapFragment) getFragmentManager()
            .findFragmentById(R.id.map)).getMap();

    Marker hamburg = mapFragment.addMarker(new MarkerOptions().position(HAMBURG)
            .title("Hamburg"));
    Marker kiel = mapFragment.addMarker(new MarkerOptions()
            .position(KIEL)
            .title("Kiel")
            .snippet("Kiel is cool")
            .icon(BitmapDescriptorFactory
                    .fromResource(R.drawable.icon)));

Isso se baseia em um tutorial que encontrei online. O problema é que continuo recebendo uma NullPointerException onde inicializo o mapFragment e não sei por que. Alguém sabe por que isto poderia estar acontecendo?

Muito grato por qualquer ajuda.

LogCat:

java.lang.NullPointerException
        at com.example.sv_laptop03.snapchain.Profile.onCreateView(Profile.java:65)
        at android.support.v4.app.Fragment.performCreateView(Fragment.java:1789)
        at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:955)
        at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1138)
        at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:740)
        at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1501)
        at android.support.v4.app.FragmentManagerImpl.executePendingTransactions(FragmentManager.java:490)
        at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:141)
        at android.support.v4.view.ViewPager.populate(ViewPager.java:1105)
        at android.support.v4.view.ViewPager.populate(ViewPager.java:951)
        at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1473)
        at android.view.View.measure(View.java:16831)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5245)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
        at android.view.View.measure(View.java:16831)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5245)
        at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1410)
        at android.widget.LinearLayout.measureVertical(LinearLayout.java:695)
        at android.widget.LinearLayout.onMeasure(LinearLayout.java:588)
        at android.view.View.measure(View.java:16831)
        at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5245)
        at android.widget.FrameLayout.onMeasure(FrameLayout.java:310)
        at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2586)
        at android.view.View.measure(View.java:16831)
        at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2189)
        at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1352)
        at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1535)
        at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1249)
        at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6364)
        at android.view.Choreographer$CallbackRecord.run(Choreographer.java:791)
        at android.view.Choreographer.doCallbacks(Choreographer.java:591)
        at android.view.Choreographer.doFrame(Choreographer.java:561)
        at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:777)
        at android.os.Handler.handleCallback(Handler.java:730)
        at android.os.Handler.dispatchMessage(Handler.java:92)
        at android.os.Looper.loop(Looper.java:176)
        at android.app.ActivityThread.main(ActivityThread.java:5419)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:525)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1046)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:862)
        at dalvik.system.NativeStart.main(Native Method)