Several users have reported that the Rhino V5 file dialog does not display mapped network drives in Windows 8/8.1. This was generally isolated to Matrix users that were running as Administrators with UAC disabled.
Under these conditions, a policy registry key called “EnableLinkedConnections” needs to be added that will enable the mapped drives to appear when running applications as an administrator.
Thanks to Dale Fugier for figuring this out.
-Added 25 February 2014