I'm so happy Mario Kart Wii is still active. The fact that I have no issue find 12 people rooms almost 7 years after the servers were shut down is so amazing. :
Required Wiimmfi Patcher update for Mario Kart Wii - Page 19 - Wiimmfi (English) - Wii-Homebrew.com Board
Wiimmfi support broken with recent Wiimmfi update · Issue #45 · Fledge68/WiiFlow_Lite · GitHub
Wiimmfi status codes meaning | GBAtemp.net - The Independent Video Game Community