You can compete against other players on the court in the Mario Tennis Aces Pre-launch Online Tournament this weekend, but many have started to encounter the error code 2306-0820 when attempting to play online.
The same error code was seen in the ARMS Global Testpunch and the Splatoon 2 Global Testfire, and, accompanied with the error messagee “This service is currently unavailable,” simply means that you are trying to play the Mario Tennis Aces Pre-launch Online Tournament outside of the hours that it is scheduled to be live in your region.
For those in the United States, the Mario Tennis Aces: Pre-launch Online Tournament demo is only playable from 6pm PDT on Friday 1st June until 11.59pm PDT on Sunday 3rd June.
Those in Europe can play from 3pm BST (4pm CEST) on Friday 1st until 11.59pm BST on Sunday 3rd June (12.59am CEST on Monday 4th June).
You can play as Mario, Peach, Yoshi and Bowser in online multiplayer matches in a tournament format, or get some practice in against a computer-controlled opponent in one-off single-player tennis battles.
You will earn points based on your performance as you advance through the tournament stages, with the chance to unlock another five characters: Waluigi, Toad, Spike, Rosalina and Chain Chomp.