Hello! Today my WiiU began to freeze while loading software. I noticed as I was going to play Mario Kart 8. Which, until today, was working perfectly fine. I reviewed that the disc wasn't scratched (it isn't) tried other WiiU games (they also froze on the loading screen), downloaded software such as a demo, tried to go to the Wii menu to which it failed, couldn't load the console settings and finally tried to start the Mii maker just to see if it worked but it did froze at the loading screen. This "freezing" goes like this: the screen shows the game/software image, it plays the music for a while (around 20 seconds) and then nothing. However I was able to navigate and see posts in Miiverse.
Another thing that also happened today, but I don't know if they are related, is that the console lost the pairing with the WiiU Pro Controller and Wii controlers, but not with the Wii Pad.
I looked on google for possible solutions and I tried the advice to unplug the console for 10 seconds but the issue was still present.