Cannot get the search path to work in Rhino for windows 10

Hello all,
When I try to create a new search path in Rhino, it will not access the file only the folder that its in, and that folder cannot be opened?
Can anyone suggest a solution for this? I thought it might be Windows but I have no problem accessing the files within the folders with any other program. I am hosting my files on Dropbox if that makes any difference?