A few days ago, I started up the wii mode on wii u. When I pressed A at the health warning screen a message popped up that said the files are corrupted. I turned off the system and rebooted it and it has worked fine since. All of my save data is still there. Should I be concerned about it happening again and maybe it even causing damage to save data?
I made backup save data of my favorite games a sd card just to be safe.