Can not open folder for subsheets

Hi, I use Kicad 8.0 and now try to use hirachical sheets. I can generate subsheets and their link seems to work, however, the folders do not show the ‘+’ sign, which should open the folder and display the list of files
Project
(see picture).

Those folders have file types that KiCad doesn’t use/mess with. So as far as KiCad is concerned . . . they are empty, so nothing to show . . . I think.

Hierarchical sheets should only be opened by navigating to them from the root sheet to ensure the internal book-keeping of them is handled correctly. They used to be displayed in the project explorer in earlier versions, but that was removed.

thanks, I understand now. I admit that I thought about using it to save different versions/variants of a circuit, so opening in the folder would make it easy to go to them. I do see your reasoning