always use the upper slot on the back side of the wiiu, not the lower one (upper one for wiiu, lower one for wii)
your hdd is formated as wbfs and your roms are isos? seriously? what? ... either use wbfs format and wbfs roms or use ntfs file system and iso roms
roms are at hdd .... funny guy, that explains nothing.. in which folder? if you use ntfs format and iso roms, then put them into a folder called "wbfs"