Some players are experiencing an issue with their Pokémon Go application, where they see an “error 0” appearing on their screen. It’s a reasonably annoying error some players can encounter, especially when the game servers are in full force. It’s a weird error because most standards mean there’s no error to report, and the game should be working correctly. However, some players have noticed it prevents them from logging into the game, shows up for a brief moment, or even prevents them from sending gifts.
Unfortunately, the only known way to deal with the problem is restarting your Pokémon Go application and starting over. If you continue to see this error even after restarting the game, you may want to wait for the Pokémon Go servers to tone slightly. It occurs when a lot of players are attempting to play all at once, around the world, especially during Pokémon Go Fest 2020.
To take more drastic measures, you may want to try uninstalling your game and downloading it again to your smartphone. It’s not the best choice, and many may be against it, but it’s a good option to be rid of it. You want to make sure you can write down any of your trainer account information before doing so, or remembering what email address you have associated with your Pokémon Go account.