Android : PendingIntent not being launched from Notification

I've tried about 20 different StackOverflow answers and NONE are working!

Just want to launch an activity from my notification I bring up. It's not working. It isn't doing anything, If I go to my home screen and click on it, it doesn't even bring up the application.

I've added a bunch of stuff since the beginning, so sorry for all the stuff that may not even be needed. I just keep looking through SO and trying solutions.

private void sendNotification(String msg, String cont, String title) {
    mNotificationManager = (NotificationManager) getApplicationContext().getSystemService(Context.NOTIFICATION_SERVICE);
    //        this.getSystemService(Context.NOTIFICATION_SERVICE);
Log.d("msg",msg);

int requestID = (int) System.currentTimeMillis();
Intent notificationIntent = new Intent(getApplicationContext(), WalkerRequest.class);
notificationIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
Log.d("Intent","setting content intent");
PendingIntent contentIntent = PendingIntent.getActivity(this, requestID, notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT
        | PendingIntent.FLAG_ONE_SHOT);

NotificationCompat.Builder mBuilder =
        new NotificationCompat.Builder(this)
                .setSmallIcon(R.drawable.paw_icon)
                .setContentTitle(title)
                .setStyle(new NotificationCompat.BigTextStyle()
                        .bigText(cont))
                .setContentText(cont);
mBuilder.setContentIntent(contentIntent);
mNotificationManager.notify(NOTIFICATION_ID, mBuilder.build());
}