SecurityException: Binder invocation to an incorrect interface

Question

I get the Error message: "Binder invocation to an incorrect interface" on this code:

IBluetoothA2dp ibta = a2dp.connect2.Bt_iadl.ibta2;
    try {
        if (ibta != null && ibta.getConnectionState(device) == 0)
            ibta.connect(device);
        else
            ibta.disconnect(device);

    } catch (Exception e) {
        Log.e(LOG_TAG, "Error " + e.getMessage());
    }

The error comes on ibta.getConnectionState(device)

That's what I do before:

public static ServiceConnection mConnection = new ServiceConnection() {

        @Override
        public void onServiceConnected(ComponentName name, IBinder service) {

            mIsBound = true;
            ibta2 = IBluetoothA2dp.Stub.asInterface(service);
            sendIntent();
        }

        @Override
        public void onServiceDisconnected(ComponentName name) {
            mIsBound = false;
        }
    };

And here is the hierarchy how I set up my packages with the .aidl :

What I'm doing wrong. I read this question: SO-Question . But I didn't know exactly what I'm doing wrong.