A main window can be closed with one of the following methods:
Click the x in the title bar of the main window.
Button Save and close in the toolbar.
Menu File / Close / Window.
Closing a level
If you have made changes to the dataset and have not saved them yet, a security prompt prevents data loss.
When closing a main window, the corresponding branch of the tree is collapsed and the main window of the parent branch is displayed. If this is the main window to a level folder, the level is closed.