Gentleman, stop your engines
Some Mario Kart Tour players are currently dealing with a major issue. We’re not sure of the reason yet, but select players are unable to even open the game. Trying to start things up causes and error, and the game simply won’t function.
Nintendo is aware of this issue, and they’re looking into a fix right now. You can see the Big N’s full statement on the matter below.
Some Mario Kart Tour players are experiencing an error which is preventing the application from starting. We are currently investigating the issue. Thank you for your patience.