PopupWindow $BadTokenException: Unable to add window -- token null is not valid
<p>I have the following error when showing a PopupWindow.
The errors are triggered by the line:</p>

<pre><code>checkInPopup.showAtLocation((ViewGroup) mapView.getParent(), Gravity.CENTER_HORIZONTAL, 0, 0);
</code></pre>

<p>mapView is a MapView and nothing is null. 
The stacktrace:</p>

<pre><code>01-08 18:00:09.402: E/AndroidRuntime(27768): Caused by: android.view.WindowManager$BadTokenException: Unable to add window -- token null is not valid; is your activity running?
01-08 18:00:09.402: E/AndroidRuntime(27768):    at android.view.ViewRootImpl.setView(ViewRootImpl.java:513)
01-08 18:00:09.402: E/AndroidRuntime(27768):    at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:301)
01-08 18:00:09.402: E/AndroidRuntime(27768):    at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:215)
01-08 18:00:09.402: E/AndroidRuntime(27768):    at android.view.WindowManagerImpl$CompatModeWrapper.addView(WindowManagerImpl.java:140)
01-08 18:00:09.402: E/AndroidRuntime(27768):    at android.view.Window$LocalWindowManager.addView(Window.java:537)
01-08 18:00:09.402: E/AndroidRuntime(27768):    at android.widget.PopupWindow.invokePopup(PopupWindow.java:988)
01-08 18:00:09.402: E/AndroidRuntime(27768):    at android.widget.PopupWindow.showAtLocation(PopupWindow.java:845)
01-08 18:00:09.402: E/AndroidRuntime(27768):    at android.widget.PopupWindow.showAtLocation(PopupWindow.java:809)
01-08 18:00:09.402: E/AndroidRuntime(27768):    at com.geoloc.ActivityCheckIn.onCreate(ActivityCheckIn.java:50)
01-08 18:00:09.402: E/AndroidRuntime(27768):    at android.app.Activity.performCreate(Activity.java:4465)
01-08 18:00:09.402: E/AndroidRuntime(27768):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
</code></pre>

<p>This is the code from my activity (that extends MapActivity) </p>

<pre><code>    protected void onCreate(Bundle icicle) {
    super.onCreate(icicle);
    setContentView(R.layout.checkin);
    mapView = (MapView) findViewById(R.id.mapview);

    LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    checkInPopup = new PopupWindow(inflater.inflate(CHECK_IN_POPUP_LAYOUT, null, false));
    checkInPopup.setOutsideTouchable(true);
    checkInPopup.setHeight(100);
    checkInPopup.setWidth(200);
    checkInPopup.showAtLocation((ViewGroup) mapView.getParent(), Gravity.CENTER_HORIZONTAL, 0, 0);
}
</code></pre>

<p>Thank you for sharing your thoughts</p>
