That's the single biggest mistake you can make with Wii U modding.Now i bricked wiiu. I was able to go to wiiu menu in sysmenu and tried to run haxchi but it freezed. I was trying to go to HL to dump wiiu nand, but with no luck, so I decided to factory reset it while CBHC installed.
Now, I boot to an error screen. Error Code: 160-0101
Im officially screwed with no backup nand and bricked wiiu. bummer
Sadly I don't think there's a fix for it.
But hey, at least a bare Wii U with no gamepad and cables is pretty cheap.