If your Wii U has to update, make sure it’s done during a clear day with no chance of a power outage.
Reports have been surfacing stating the system will completely brick if the power goes out during a firmware update. Journalist Ben Fritz reported on Twitter that he unplugged his Wii U during an update because of the time it would take, and when it plugged back in it bricked. He added that there is no “cancel” option available.
Another gamer reported a connect timing out caused it to brick.
Nintendo of America warns “please do not power down or unplug your system while downloading updates. Doing so may cause damage to your Wii U.”