While he can't NUSspli should be able to. There's a reason it includes options to download to USB and install fom there, too.You can't create a folder on the usb drive. The wii u os can, yes. But not you. All the games which you want to install, must be on the sd card.
First off you don't want to use SSDs on the Wii U: The Wii U tends to do a lot of writes which will wear out the SSD pretty fast. Also the bottleneck on the Wii U is USB 2.0, so a slow HDD is more then enough / you won't benefit from high-speed storage mediums.I plugged in on USB1 a SDD hard drive with Y cable and let the WiiU format it but the Nusspli always gives me a "directory error" when downloading games to USB.
Anyway, try to connect the Y cable to a (powerfull) wall charger. If that doesn't help: What's the full error message?
//EDIT: Also could you test a USB stick? Don't use it for long, just format it on the Wii U, then try to download a small title to it. This test will check for multiple issues (brownout, bad storage / adapter combination, bad Y cable).
//EDIT²: Also make sure you're using the newest NUSspli version. There where some USB issues in the past and as it was pre-installed it might be a bugged version.
Last edited by V10lator,