Reopen a closed window

Hello,

I try to re-open a window that is closed without any success.
Indeed, ui.Main is not my main program loop and I want to open window on demand (it's a subroutine of my main program).
When registering window to ui.Main(myWindow) and then call Destroy() from myWindow, I'm not in position to call the Main again with the same argument.
Getting into the code, it appears that myWindows is considered as already registered and couldn't get it open once again.

How should I handle this specific case?