How to detect dialog windows?

I need Keyboard Maestro to detect the following dialog box:


It is from the plugin Awesome TTS for Anki 2.1.

The text on the dialog box usually changes, but it will always have "During processing, there were".

How can I detect this box?

I have tried using:

Pause Until Conditions are Met
--> Front applications contains During processing, there were

But it doesn't seem to work. Any ideas?

PS. Keyboard Maestro is awesome. It is one of the best apps on Mac!

You can use Pause until a Button with name "OK" is visible!

and then let KM click that button


Thank you so much. That worked perfectly. Thanks again!