Android 'Unable to add window -- token null is not for an application' exception

Solution 1:

I'm guessing - are you trying to create Dialog with an application context? Something like this:

new Dialog(getApplicationContext());

This is wrong. You need to use an Activity context.

You have to try like:

new Dialog(YourActivity.this);

Solution 2:

You can continue to use getApplicationContext(), but before use, you should add this flag: dialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT), and the error will not show.

And don't forget to add permission:

<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />

Solution 3:

In my case I was trying to create my dialog like this:

new Dialog(getApplicationContext());

So I had to change for:

new Dialog(this);

And it works fine for me ;)