title: iOS10 UNNotificationServiceExtension not called
body: <p>Im implementing new iOS10 extension to use rich notifications. Im trying to test it on push notifications but is not working, I just receive a simple notification and is not going through the extension.</p>
  
  <p>I did all that it's specified in the official sites and some other places:</p>
  
  <ul>
  <li>I have my app up and running with push notifications and the right provisioning profile</li>
  <li>I added a new target to my app, a Notification Service Extension</li>
  <li>Implemented my own code (it doesn't matter really because is not even entering to the new class)</li>
  <li>Also I had to set a provisioning profile for this extension, I just use one with a wildcard, I don't see any documentation specifying if the extension target has to enable push notifications capability, in that case I would need a specific provisioning for this one, at the moment I just use a wildcard prov, anyway it matches (it must match) the profile I use in the app target, and push notifications capability is enabled for the app target only.</li>
  <li>I added UNNotificationExtensionCategory and NSExtensionPointIdentifier. Also Im sending the category as part of the push payload from the server.</li>
  </ul>
  
  <p>As I said, I get the notification but never goes through the extension. I see how the OS tries to load the extension but then throws an error with no relevant description to identify the problem:</p>
  
  <pre><code>Dec 31 21:00:00 iPhone SpringBoard(libextension.dylib)[51] &lt;Notice&gt;: calling plugIn beginUsing:   
  Dec 31 21:00:57 iPhone pkd[86] &lt;Notice&gt;: assigning plug-in com.test.app.NotificationWithAttachmentExtension(1.0) to plugin sandbox   
  Dec 31 21:03:57 iPhone pkd[86] &lt;Notice&gt;: enabling pid=51 for plug-in com.test.app.NotificationWithAttachmentExtension(1.0) 38BB5FF1-2597-42E0-B950-169DBFA80573 /private/var/containers/Bundle/Application/A8C47706-C0EC-4FB1-ABA7-0118372F6900/testapp.app/PlugIns/NotificationWithAttachmentExtension.appex   
  Dec 31 21:00:53 iPhone SpringBoard(PlugInKit)[51] &lt;Notice&gt;: plugin com.test.app.NotificationWithAttachmentExtension interrupted   
  Dec 31 21:03:56 iPhone SpringBoard(PlugInKit)[51] &lt;Notice&gt;: Hub connection error Error Domain=NSCocoaErrorDomain Code=4097 "connection to service named com.test.app.NotificationWithAttachmentExtension" UserInfo={NSDebugDescription=connection to service named com.test.app.NotificationWithAttachmentExtension}   
  Jun 29 13:33:36 iPhone SpringBoard(libextension.dylib)[51] &lt;Notice&gt;: PlugInKit error in beginUsing:   
  Jun 17 23:33:04 iPhone SpringBoard(libextension.dylib)[51] &lt;Notice&gt;: killing invalid plugIn   
  Dec 31 21:00:00 iPhone SpringBoard(UserNotificationsServer)[51] &lt;Error&gt;: Extension error whilst trying to modify push notification F502-9B36: Error Domain=NSCocoaErrorDomain Code=4097 "connection to service named com.test.app.NotificationWithAttachmentExtension" UserInfo={NSDebugDescription=connection to service named com.test.app.NotificationWithAttachmentExtension}   
  Dec 31 21:00:00 iPhone SpringBoard(UserNotificationsServer)[51] &lt;Notice&gt;: [com.test.app] Saving notification F502-9B36   
  Dec 31 21:00:00 iPhone SpringBoard(libextension.dylib)[51] &lt;Notice&gt;: completed calling plugIn beginUsing: for pid: 0  
  </code></pre>
  
  <p><strong>Relevant extension .plist:</strong></p>
  
  <pre><code>  &lt;dict&gt;
      &lt;key&gt;NSExtensionAttributes&lt;/key&gt;
      &lt;dict&gt;
        &lt;key&gt;UNNotificationExtensionCategory&lt;/key&gt;
        &lt;string&gt;attachmentCategory&lt;/string&gt;
        &lt;key&gt;UNNotificationExtensionInitialContentSizeRatio&lt;/key&gt;
        &lt;real&gt;1&lt;/real&gt;
      &lt;/dict&gt;
          &lt;key&gt;NSExtensionPointIdentifier&lt;/key&gt;
          &lt;string&gt;com.apple.usernotifications.service&lt;/string&gt;
          &lt;key&gt;NSExtensionPrincipalClass&lt;/key&gt;
          &lt;string&gt;$(PRODUCT_MODULE_NAME).NotificationService&lt;/string&gt;
    &lt;/dict&gt;
  </code></pre>
  
  <p>What's wrong or missing?</p>