The error message is pretty explicit: you can't use ".." in a path to go above teh root folder of your website.
".." is relative the the folder the current page is in: so it the current page is in teh top level folder, you can't use ".." at all, as it would take you outside the site area and into the "list of sites on this host" area!
Use an absolute path reference rather than a relative one.
Absolute and Relative Paths[
^]