Wii USB Flash Drive compatibility

I got a 256 gb usb flash drive for my wii u and it said I couldn't format it because its write protected. However, I had my friend who is pretty good with technical stuff check it out and he said that the usb flash drive is not write protected and that it has something to do with the wii u. Does the wii u support every usb flash drive or does it only support name brand ones because I had a sony one work but the generic one I was trying to format wouldn't work.

Maybe the drive requires more power than the WiiU will provide? Might need one of the kinds that you have to plug in separately. Or if this is the issue maybe it could be split to both USB ports for more juice...

USB splitter

Might need to be formated into FAT32MonsieurX

Might need to be formated into FAT32MonsieurX

Might need to be formated into FAT32MonsieurX