The two games have been offline since March after Nintendo took them offline to fix a “vulnerability related to online play.” While Nintendo hasn’t given details about the vulnerability, a data miner reported that the issue was likely one that could let a bad actor take over a console by connecting to it online.
To play the two games online again, you’ll need to download a new update. However, Nintendo cautions that if more issues pop up, it may have to discontinue online multiplayer for Mario Kart 8 and Splatoon “at short notice.” Fingers crossed that doesn’t happen; Mario Kart 8 and Splatoon were among Nintendo’s bestselling titles on the Wii U, so it would be a shame if those people who are still using Nintendo’s older console couldn’t play online anymore.
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