Earlier this month, Tree of Savior took the drastic step of removing itself from Steam and shutting the doors to any new players. This was done in response to problems with server instability, lag, and a flood of bots. Current players were allowed to log in during this period, and IMC Games used the reprieve to swing the mighty banhammer against the naughty minority.
The good news is that the player immigration embargo is now at an end: “We would like to welcome all the new saviors! The servers are now open to allow new players to join the game. Our sincere thanks for your understanding and patience up to this point and appreciate your support.”
Tree of Savior is also back up on Steam.
Source: Tree of Savior. Thanks Connor for the tip!