I recently used Wii U along with 8 games off craigslist. Everything seems to be working, except one of the games, which was Super Smash Bros Wii U. This problem seems to only happen with that single game, as all the other games read fine. I have contacted the seller and he he hadn't touched it in months and it worked fine before. The game itself doesn't seem to be heavily damaged or anything. But you can see some light scratches under light if you are looking for them. I tried cleaning it gently using a microfiber cloth (and tried it multiple times) but I still had no luck getting the game to be recognized. I also tried to cleaning it gently with a bit of soap and water, which still didn't work. If anyone has experienced this or have any ideas on what I should do, I would greatly appreciate it.