Virtualbox Drag and drop from Windows Host cannot handle UNC folders (for me it doesn't work with 7.0.26).
Drag-and-drop is generally fragile: if error occurs due to misplacing on top of a program or another reason - subsequent drops in the same session may not work, dragging a lot of files/subfolders sometimes doesn't work, mouse clicks become erratic after drag-and-drop (especially if there was an error) (mouse cursor moves, but clicking doesn't do anything or dragging the mouse stops working inside the guest Windows after drag-and-drop from host to guest fails), etc.
Virtualbox Drag and drop from Windows Host cannot handle UNC folders (for me it doesn't work with 7.0.26).
Drag-and-drop is generally fragile: if error occurs due to misplacing on top of a program or another reason - subsequent drops in the same session may not work, dragging a lot of files/subfolders sometimes doesn't work, mouse clicks become erratic after drag-and-drop (especially if there was an error) (mouse cursor moves, but clicking doesn't do anything or dragging the mouse stops working inside the guest Windows after drag-and-drop from host to guest fails), etc.