IllegalArgumentException: provider doesn't exisit: null on Maps V1

I'm using Google Maps API V1. I have this error :

     java.lang.IllegalArgumentException: provider doesn't exisit: null

This is my code :

    locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
    Criteria criteria = new Criteria();
    criteria.setAccuracy(Criteria.ACCURACY_FINE);
    String provider = locationManager.getBestProvider(criteria, true);

    if (provider != null)
    {

        startTime = System.currentTimeMillis(); 

        geoLocTimeOutTask = new GeoLocTimeOutTask();
        geoLocTimeOutTask.execute();

        locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);

        locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
    }
    else
    {
        geoLocCallbackObj.geoLocationCallback(tagCallback); 

    }

I understand the error, bu my question is, whay the device put me this error ? And how can I avoid this please ?