Hi ,i have the exact same problem ,i'm using Haxchi on vs 5.5.2 (the DS game method).Games i have on disk work just fine .I tried via UsbHelper to instal to nand(i have a Y cable for external HDD ,but my WiiU doesn't recognize it even with it ,dunno why,beacuse it's a usb 2 HDD - maybe somne can...