Hello SGaist, Thank you for the reply. I am using Windows 10 Home edition with Qt 5.12.4. The problem is only in windows, I tried linux and macos and both work as intended. I tried to do a minimal compilable example that reproduces the behaviour but i couldn't, the full screen does not prevent the menubar to show the contents for a simple example. I don't know if the status bar or some of the actions related to it are interfering with the menu bar but that is my best guess. I don't have any other concrete thing or idea to check. I don't have anything that uses Qt::WindowStaysOnTopHint too.

That's not how it works and not something I would expect either. The mdi sub-windows will only extend in the mdi area, nothing more. The behavior you are looking for, you'll have to implement yourself.

Hi, IIRC, that's part of the GNOME Human Interface Guidelines so there's no much you can do from a Qt point of view.

Hello, That not the problem here. If i understand correctly, the OSX Application Menu is translated by Qt, not my application. The problem occurs only with QtQuick and on a OSX no-english. So why i must do give a translated file created by me for QtQuick and not for QtWidgets ? (And not the translated files qt) Regards, nelbok

Hi and welcome to devnet, Do you mean that if you use the qt_fr.qm file everything is going well but if you add your own translation it starts acting up ?ä

You're welcome ! SInce everything is OK now, please update the thread title prepending [solved] so other forum users may know a solution has been found :) Also, while browsing the forum, consider up-voting the answers that helped you, it will make them easier to find for other users :)

IIRC, having at first position allows the forum to show it more nicely on the lists

Hi, Did you put some actions within your menubar? IF not, the menubar is there, but empty, so almost invisible. If you are using the designer, it should be easy enough. Setting a layout is just clicking the top icons which layout you need. The resizing in designer is the resize you get in your end program. What happens if you open up an example and run it? Is there any difference between debug and release versions?