In Win 10 I have the Explorer pinned to the taskbar.
I can right-click the icon as usual and am being shown the usual menu with several folders attached to it.
However, since a few days, I am not able to use the shown menu's entries anymore. I can left-click on a menu entry, but the clicked folder doesn't open, instead, Win10 complains that the folder in question doesn't exist or has been moved (well, they still are all there).
I can right-click a menu entry and choose an action from the popup menu (say, remove from the list), but in that case, simply nothing happens: entries aren't removed.
Double-clicks on shortcut folders directly on the desktop work as usual.