Steam is the leading client for distributing games and maintaining their online servers for game play.
It’s likely that you didn’t restart your client after Steam got updated or if you installed a fresh game.
Whenever an installation or download takes place, a lot of configurations occur and it is necessary to restart your PC for them to take place.
Or it might be the case that your server is overloaded/down for maintenance.
We can try changing your download region and see if this fixes the problem at hand.
Flushconfig flushes and reloads the configurations for each of the applications/games installed in your PC.
Most operating systems are designed to cache the DNS records.Simple reboot your PC and try running the game again.If the problem still persists, we can follow the solutions below.This problem can occur due to many different reasons.It all depends on your software and hardware as all the users have different configurations.We can try reducing your bandwidth to something acceptable and restarting Steam.