On Windows 10, GDevelop Desktop App 5.4.205, if you absentmindedly double click this menu on any object
It will open the menu and it will open the object window at the same time. If you then further absentmindedly choose to delete or cut the object from the menu, with the object window open, the object window becomes stuck open. It will not close by hitting X or Close or Apply or Esc…
The only way to close it is to either exit out of GDevelop by shortcut or the X (after saving your work with the shortcut keys), or to hit one of the tabs in the object window, for example the Behavior tab. That will close the object window and create an error like this
The error does not close when you hit the X. But once you get the error, you have access to the buttons to save your project if you did not do so with the shortcut, and also to close the scene editor tab that the deleted object was in. If you close the scene editor tab, you can reopen it and everything is normal, the object is deleted and the error is gone.
The reason I think this is a bug is because this does not happen in the web version on the same Windows 10 pc, Nor does it happen on the desktop apps (all v5.4.205) I have installed on macOS Sonoma and Zorin OS. In all those instances, double clicking that same menu button only results in the menu opening and closing in quick succession. It does not cause the object window to open.
I do not know if this happens on Windows 11 because I upgraded my Windows 11 to Zorin OS.