Failed to start the gyroscope sensor

Question

I am trying to develop a Location-Based AR application in Android using metaioSDK 5.5.2 and when I start the application it tells me that it couldn't start the gyroscope sensor, and I have a NullPointerException. Here is the Log file:

  06-05 00:59:46.487: E/metaio-java(13855): Failed to start the gyroscope sensor
  06-05 00:59:46.487: E/metaio(13855): 301: Failed to start the following quired sensors by the tracking configuration: 128

  06-05 00:59:46.492: E/metaio-java(13855): Error stopping face detection: java.lang.RuntimeException: stop face detection failed 
   06-05 00:59:46.497: E/AndroidRuntime(13855): FATAL EXCEPTION: main
  06-05 00:59:46.497: E/AndroidRuntime(13855): Process: com.mada.iacob.test, PID: 13855
  06-05 00:59:46.492: E/metaio-java(13855): Error stopping face detection: java.lang.RuntimeException: stop face detection failed
  06-05 00:59:46.497: E/AndroidRuntime(13855): FATAL EXCEPTION: main
  06-05 00:59:46.497: E/AndroidRuntime(13855): Process: com.mada.iacob.test, PID: 13855
  06-05 00:59:46.497: E/AndroidRuntime(13855): java.lang.IllegalStateException: Could not execute method of the activity
  06-05 00:59:46.497: E/AndroidRuntime(13855):  at android.view.View$1.onClick(View.java:3969)
  06-05 00:59:46.497: E/AndroidRuntime(13855):  at android.view.View.performClick(View.java:4640)
  06-05 00:59:46.497: E/AndroidRuntime(13855):  at android.view.View$PerformClick.run(View.java:19425)
  06-05 00:59:46.497: E/AndroidRuntime(13855):  at android.os.Handler.handleCallback(Handler.java:733)
  06-05 00:59:46.497: E/AndroidRuntime(13855):  at android.os.Handler.dispatchMessage(Handler.java:95)
  06-05 00:59:46.497: E/AndroidRuntime(13855):  at android.os.Looper.loop(Looper.java:146)
  06-05 00:59:46.497: E/AndroidRuntime(13855):  at android.app.ActivityThread.main(ActivityThread.java:5593)
  06-05 00:59:46.497: E/AndroidRuntime(13855):  at 
java.lang.reflect.Method.invokeNative(Native Method)
  06-05 00:59:46.497: E/AndroidRuntime(13855):  at java.lang.reflect.Method.invoke(Method.java:515)
  06-05 00:59:46.497: E/AndroidRuntime(13855):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
  06-05 00:59:46.497: E/AndroidRuntime(13855):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
  06-05 00:59:46.497: E/AndroidRuntime(13855):  at dalvik.system.NativeStart.main(Native Method)
  06-05 00:59:46.497: E/AndroidRuntime(13855): Caused by: java.lang.reflect.InvocationTargetException
  06-05 00:59:46.497: E/AndroidRuntime(13855):  at java.lang.reflect.Method.invokeNative(Native Method)
  06-05 00:59:46.497: E/AndroidRuntime(13855):  at java.lang.reflect.Method.invoke(Method.java:515)
  06-05 00:59:46.497: E/AndroidRuntime(13855):  at android.view.View$1.onClick(View.java:3964)
  06-05 00:59:46.497: E/AndroidRuntime(13855):  ... 11 more
  06-05 00:59:46.497: E/AndroidRuntime(13855): Caused by: java.lang.NullPointerException
  06-05 00:59:46.497: E/AndroidRuntime(13855):  at com.mada.iacob.test.ARActivity.onGPSButtonClick(ARActivity.java:141)
  06-05 00:59:46.497: E/AndroidRuntime(13855):  ... 14 more

and here is a piece of code:

public void onGPSButtonClick(View v) {
    boolean result = metaioSDK.setTrackingConfiguration("GPS");

    metaioSDK.setLLAObjectRenderingLimits(100,1000);

    Log.d("TestMETAIO", "aici9");
    mMan.setVisible(false);
    mSphere.setVisible(false);

    Log.d("TestMETAIO", "aici 10");
    mRadar.setVisible(true);
    Log.d("TestMETAIO", "aici 11");
    mBridge.setVisible(true);
    mDowntown.setVisible(true);
    mTwin.setVisible(true);

    MetaioDebug.log("Markerless tracking data loaded" + result);
}

@SuppressWarnings("deprecation")
private void loadGPSContent() {
    try {
        mBridge = metaioSDK.createGeometryFromImage(createBillboardTexture("Bridge"));
        mDowntown = metaioSDK.createGeometryFromImage(createBillboardTexture("Downtown"));
        mTwin = metaioSDK.createGeometryFromImage(createBillboardTexture("Twin"));

        updateGeometries(mSensors.getLocation());

        mRadar = metaioSDK.createRadar();
        mRadar.setBackgroundTexture(AssetsManager.getAssetPath("assets3/radar.png"));
        mRadar.setObjectsDefaultTexture(AssetsManager.getAssetPath("assets3/yellow.png"));
        mRadar.setRelativeToScreen(IGeometry.ANCHOR_TL);

        mRadar.add(mBridge);
        mRadar.add(mDowntown);
        mRadar.add(mTwin);

        mBridge.setVisible(false);
        mDowntown.setVisible(false);
        mTwin.setVisible(false);


    } catch(Exception e) {
        Log.d("EXCEPTIE", "aici 10"+e);
    }
}

Please if anyone could help me. I couldn't find anything on the internet, and it is really important.