Alexander, i used wii flow 4.1. Using the mac I opened up a game file to the .iso I have then used Witgui to transfer and convert the game to my portable USB external hard drive and also to a USB 8gb stick. On the mac the files are on both. On the wii u when I insert either I get the following" welcome to wii flow. I have not found any games. Click install to install games, or select partition to select your partition type. I selected usb1 over the sd. But neither bring up the game?? Any suggestions?