GCM - pubSub.subscribe not working
<p>I'm using GCM in my android client and I already can push notification from my App server to Android client.</p>

<p>But I cannot subscribe for a topic I use <strong>pubSub.subscribe</strong> method and pass registration token and custom topic name in the format of "/topics/mytopic".
Here are the thing I'm done so far:</p>

<ul>
<li>I wrap the method inside try and catch and it doesn't throw any exceptions.</li>
<li>I have debugged HTTP via Fiddler but when it does not send any request.</li>
<li>I try get information of token id via <a href="https://iid.googleapis.com/iid/info/IID_TOKEN" rel="nofollow">https://iid.googleapis.com/iid/info/IID_TOKEN</a> but it doesn't return any subscribed topics for the client.</li>
</ul>

<p>here the publish code in android intent service:</p>

<pre><code>GcmPubSub pubSub = GcmPubSub.getInstance(this);
try
{
    pubSub.subscribe(token, "/topics/mytopic",null);
} catch (IOException e)
{
    e.printStackTrace();
}
</code></pre>