I followed FlimFlam69's 5.5.1 Kernel Exploit Guide if that is relevant. (You can find it on r/wiiuhacks.)
Oops, i didn't have my SD card in my Wii U.That usually happens when you don't have the correct files on the sd card, it gets corrupted, or there is no sd card detected. If you are using a micro sd adapter i would recommend trying another adapter as the original could be faulty. If not, then double check if the files are there and intact.
All of the above also the wiiu sd card slot is very temperamental try blowing into it as the smallest bit if dust makes it not work lol well blowing the sd card slot always works for me at least when I get that error brings back memories of having to do that with my Nes back in the 90s. Edit never mind op sorted problem at same time I posted this lolThat usually happens when you don't have the correct files on the sd card, it gets corrupted, or there is no sd card detected. If you are using a micro sd adapter i would recommend trying another adapter as the original could be faulty. If not, then double check if the files are there and intact.
Sandisk adapters are trash. I've had 3 fail on me.I have "FSGetMountSource Failed."
then change to another micro sd adapter (sandisk)