Marker's not showing: Google Map Android

Question

In my project I'm loading my maps programmatically on a fragment. However, adding markers on this map is not working. No error is shown but the marker is not on the map as well.

I'm following the specification so i have no idea why it is not working. (Lat and Lng of the marker and the camera are the same)

My Fragment Code

public class MainMapFragment extends Fragment implements OnMapReadyCallback {
SupportMapFragment mMapFragment;
static final LatLng LIBRARY = new LatLng(Lat, Lng);
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    return inflater.inflate(R.layout.main_map_layout,container,false);
}

@Override
public void onViewCreated(View view, Bundle savedInstanceState) {
    //Set the initial stage of the map
    //It is set on code (not on the xml) because the map is created programmatically
    GoogleMapOptions options = new GoogleMapOptions();
    CameraPosition ufv_position = new CameraPosition.Builder()
            .target(new LatLng(Lat,Lng))
            .zoom(15)
            .tilt(0)
            .bearing(40)
            .build();

    options.mapType(GoogleMap.MAP_TYPE_NORMAL)
            .compassEnabled(false)
            .rotateGesturesEnabled(false)
            .tiltGesturesEnabled(false)
            .camera(ufv_position);
    //Load the map with the given options
    mMapFragment = SupportMapFragment.newInstance(options);
    FragmentTransaction fragmentTransaction =
            getChildFragmentManager().beginTransaction();
    fragmentTransaction.add(R.id.map, mMapFragment);
    fragmentTransaction.commit();
}

@Override
public void onMapReady(GoogleMap googleMap) {

    googleMap.addMarker(new MarkerOptions()
            .position(LIBRARY)
            .title("Library")
            .icon(BitmapDescriptorFactory.fromResource(R.drawable.book)));


}

}

Answer 1

add mMapFragment.getMapAsync(this); so your onMapReady method gets called