Hi genius,

I have written a demo which is able to reproduce the bug. Please download error-demo.zip and cargo run it in MacOS. My local MacOS version is .

In a nutshell, even though the MessageDialog widget can't automatically collapse, the executing flow of the program isn't blocked. Namely, as soon as the button "Ok" on the MessageDialog widget is clicked,

1. The method ".show()" instantly returns MessageDialogResult
2. The subsequent MessageDialog with different title and message strings can be normally expanded and supersedes the old one as well.

However, the latest MessageDialog widget abnormally stays on the Desktop all the time, until the main process exits. The phenomenon merely occurs in MacOS.