diff --git a/app/src/main/java/org/y20k/trackbook/MainActivity.java b/app/src/main/java/org/y20k/trackbook/MainActivity.java
index e75c892..1075e75 100755
--- a/app/src/main/java/org/y20k/trackbook/MainActivity.java
+++ b/app/src/main/java/org/y20k/trackbook/MainActivity.java
@@ -721,8 +721,10 @@ public class MainActivity extends AppCompatActivity implements TrackbookKeys {
         Toast.makeText(this, stringResource, Toast.LENGTH_LONG).show();
         // vibrate 50 milliseconds
         Vibrator v = (Vibrator) getSystemService(Context.VIBRATOR_SERVICE);
-        v.vibrate(50);
+        if (v != null) {
+            v.vibrate(50);
 //            v.vibrate(VibrationEffect.createOneShot(50, DEFAULT_AMPLITUDE)); // todo check if there is a support library vibrator
+        }
     }
 
 
diff --git a/app/src/main/java/org/y20k/trackbook/MainActivityTrackFragment.java b/app/src/main/java/org/y20k/trackbook/MainActivityTrackFragment.java
index 6d13f83..da4269a 100755
--- a/app/src/main/java/org/y20k/trackbook/MainActivityTrackFragment.java
+++ b/app/src/main/java/org/y20k/trackbook/MainActivityTrackFragment.java
@@ -362,7 +362,7 @@ public class MainActivityTrackFragment extends Fragment implements AdapterView.O
     private void displayTrack() {
         GeoPoint position;
 
-        if (mTrack != null) {
+        if (mTrack != null && mTrack.getSize() > 0) {
             // set end of track as position
             Location lastLocation = mTrack.getWayPointLocation(mTrack.getSize() -1);
             position = new GeoPoint(lastLocation.getLatitude(), lastLocation.getLongitude());