Error #001, unauthorized device has been detected

Hey everyone, im kind of a beginner at all of this! I just got homebrew channel, usb loader GX and neogamma R9 ios 249.
I can load games normally (PAL) but for some reason when I load Mario kart, it come up with a message "Error #001, unauthorized device has been detected". then my wii freezes on that screen.

the steps i use-
1. transfer ISO to hardrive via wiibackupmanager
2. connect usb to wii and load usb loader gx
3. choose mario kart
4. Error #001, unauthorized device has been detected

any help would be much appreciated :)

How did you mod your wii? Did you use a guide here?

Im getting this on fishing resort. I used this website guide for softmod.