app startet nicht

public class MainActivity extends ListActivity {

    private static final int REQUEST_BT_ENABLE = 0x1;
   
    ListView listGeraete;
    TextView text;
    BluetoothAdapter bluetoothAdapter;
    ArrayAdapter<String> arrayAdapter;
    static private ArrayAdapter<BluetoothDevice> BtDevices = null;

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        
        bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
        text = (TextView) findViewById(R.id.txt);
        listGeraete = (ListView) findViewById(R.id.list);
        arrayAdapter = new ArrayAdapter<String>(MainActivity.this,
                android.R.layout.simple_list_item_1);
        listGeraete.setAdapter(arrayAdapter);
        registerReceiver(ActionFoundReceiver, new IntentFilter(
                BluetoothDevice.ACTION_FOUND));
    }

    // Aktivierung von Bluetooth
    public void ClickBtOn(View view)

    {
        bluetoothAdapter.enable();
        Intent enablerBt = new Intent(bluetoothAdapter.ACTION_REQUEST_ENABLE);
        startActivityForResult(enablerBt, REQUEST_BT_ENABLE);

    }

    // Deaktivierung von Bluetooth
    public void ClickBtOff(View view) {
        bluetoothAdapter.disable();

    }

    protected void onDestroy() {
        // TODO Auto-generated method stub
        super.onDestroy();
        unregisterReceiver(ActionFoundReceiver);
    }

    public void ClickBtScan(View view) {
        

        if (!bluetoothAdapter.isEnabled()) {
            Intent enableBt = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(enableBt, REQUEST_BT_ENABLE);

        }
        arrayAdapter.clear();
        

        bluetoothAdapter.startDiscovery();
    }
    
    
    
    
    
    
    
    

    private final BroadcastReceiver ActionFoundReceiver = new BroadcastReceiver() {
        public void onReceive(Context context, Intent intent) {
  
            String action = intent.getAction();
       
            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                BluetoothDevice device = intent
                        .getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                arrayAdapter.add(device.getName() + "\n" + device.getAddress());
                arrayAdapter.notifyDataSetChanged();
            }
        }
    };
    
    
    
    
    
     protected void onListItemClick(ListView l, View v, final int position, long id) {

         super.onListItemClick(l, v, position, id);
     

         if(bluetoothAdapter.isDiscovering()) {                               

                     bluetoothAdapter.cancelDiscovery();

         }



     

         Toast.makeText(getApplicationContext(), "Connecting to " + BtDevices.getItem(position).getName() + "," + BtDevices.getItem(position).getAddress(), Toast.LENGTH_SHORT).show();

    
    
    
    
     }
    
    
    
    
    
    
    

}