Using Windows 8.1 and Windows 10, I cannot navigate to mapped drives when using browse dialogs found in FTK and FTK Imager. E.g. Browse dialogs such as used when doing "Add Evidence."
Workaround 1: Type the full UNC path in the browse dialog, to path to the mapped resource.
Workaround 2: Follow this link for instructions from Microsoft on how to change registry settings that will allow your mapped drives to appear in FTK Imager.
User Account Control in Windows 8.1 and Windows 10 interferes with FTK and FTK Imager browse dialogs, in that, FTK and FTK Imager browse dialogs may not be display mapped drives.
FTK Imager, FTK Standard, FTK International.