I did a little experiment, the sample file is failing.
I'm running the system, I touch the button a lot of times and the system crashes after a while.(I've touched the button without stopping, and I think it's crashing at the 20th touch)
Using a nested window in a project I made based on the following example gives an error.
I want to enter the sub-menus by pressing the buttons.
Settings(dialog1)-> Display(dialog2)- -> Resolution(dialog3)