Receiver not registered exception error?

Question

In my developer console people keep reporting an error that I cannot reproduce on any phone I have. One person left a message saying he gets it when they try to open the set

Answer 1

Declare receiver as null and then Put register and unregister methods in onResume() and onPause() of the activity respectively.

@Override
protected void onResume() {
    super.onResume();
    if (receiver == null) {
        filter = new IntentFilter(ResponseReceiver.ACTION_RESP);
        filter.addCategory(Intent.CATEGORY_DEFAULT);
        receiver = new ResponseReceiver();
        registerReceiver(receiver, filter);
    }
}      

@Override
protected void onPause() {
    super.onPause();
    if (receiver != null) {
        unregisterReceiver(receiver);
        receiver = null;
    }
}