I recently had problems with Mario Kart 8 Deluxe connection error message whenever I go into the character select screen online and only during the day, it would connect to online players but whenever I go into the character select screen to car customization select screen it would give me a 'Connection Error'. Turns out it was my ISP's DNS that was causing the issue aside from the fact Nintendo needs to update the game so it works properly on most if not all popular ISP's, I'm in Canada and using TeckSavv internet which is very popular outsource of Rogers internet sold at a lower bulk price however Techsavvy uses it's own DNS servers which is not so great for gaming. Long story short, I found this thread from the AMD forum: https://community.amd.com/thread/200161 Here's the program link: http://www.softpedia.com/get/Network-Tools/Network-Testing/DNS-Benchmark.shtml I ran it three times and OpenDNS works best for me (I use the primary OpenDNS server) and second best was Google's Public DNS in which I use Google primary as my secondary on the Switch's internet connection settings. OpenDNS servers: https://en.wikipedia.org/wiki/OpenDNS Google Public DNS servers: https://en.wikipedia.org/wiki/Google_Public_DNS To manually change the DNS servers on the Switch first press the 'Home' button if you're not already at the Home screen then go into 'Setting' then scroll down to 'Internet' and select 'Internet Settings'. It should then show you a list of your Registered Networks, select the one you use the most (that is connected) and then select 'Change Settings'. Scroll down and select 'DNS Setting's then select 'Manual', enter the best Primary DNS you got from running the above tool and your best Secondary DNS also from the above tool. Once all done, select "SAVE" on the right hand side and exit the Switch's setting menu. All done, enjoy no more connection errors when playing online games on the Switch! - Nintendo will likely come out with a online patch for Mario Kart 8 Deluxe however until then this is a good fix and even after they patch these settings changed can be left untouched. - I have no more connection error issues with Mario Kart 8 Deluxe after changing the DNS on the Switch and online seems to load faster too, good luck! - This should also help fix the so called poor Wi-Fi on the Switch for anything internet related on the Switch unless of course your wireless router is the main problem and not the Switch's wireless hardware.