ClassNotFoundException reading a Serializable object in a class extending MapFragment in onSaveInstanceState

I have a class extending the SupportMapFragment where i load some data from backend and display the Markers. I also have another fragment which i display the details corresponding to the selected marker on the map. I am displaying the details fragment below the map in portrait mode and side by side in landscape.

public class MapDisplayFragment extends SupportMapFragment {
private ArrayList<ShowLocation> locations = null;

public void onViewCreated(View view, Bundle savedInstanceState) {
    if (savedInstanceState != null) {
    locations = (ArrayList<ShowLocation>)savedInstanceState.getSerializable("LOCATIONS");
    }
}
@Override
public void onSaveInstanceState(Bundle outState) {
  if (outState == null) {
 outState = new Bundle();
  }
  outState.putSerializable("LOCATIONS", locations);
  super.onSaveInstanceState(outState);
}

I have a class which implements Serializable which is used in the derived map class. I use the onSaveInstanceState to store the object so that i dont have to retrieve the data from the backend again. but the app crashes with java.lang.RuntimeException: Parcelable encounteredClassNotFoundException reading a Serializable object when i flip the device.

public class ShowLocation implements Serializable {
    private String geoCodeLat = Constants.EMPTY_STRING;
    private String geoCodeLng = Constants.EMPTY_STRING;
    ....
    public String getGeoCodeLat() {
       return geoCodeLat;
    }
    public void setGeoCodeLat(String geoCodeLat) {
       this.geoCodeLat = geoCodeLat;
    }

    public String getGeoCodeLng() {
       return geoCodeLng;
    }

    public void setGeoCodeLng(String geoCodeLng) {
        this.geoCodeLng = geoCodeLng;
    }
    ....
}

I have defined the layout as follows:

<LinearLayout
        android:id="@+id/layoutMapData"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"