How to set the application configuration for the Java Security Warning in SilkTest API

We SilkTest API version 18.5 (not SilkTest Classic or Workbench).

We test a web application, that might open the Java Security Warning dialog or not. If the dialog comes up, it must be confirmed. But we are not even able to check whether the dialog is present.

With "Windows Locators..." in Silk Test Classic, I got the locator of the window. Using this value, I tried:

desktop.<Window>find(locator);

expecting to get the information whether the warning dialog is present or not. But I get the exception No application configuration present.

I found some descriptions about setting the application configuration in Silk Test Classic, but they don´t help for SilkTest API.

So how can I set the application configuration for this dialog in SilkTest API?

Thanks for any idea.