The Error Code 401 message is displayed in the following situations.

■ Causes of Error Code 401

 - If an abnormal game login attempt or device environment is detected

 - If your device is missing a SIM card

 - If your device is not in the Korean time zone (code)

 - If you used an external program to run the game

 - If your device doesn't meet the minimum specifications

If possible, please close all external programs before using the game.

We also recommend using the game in a stable network environment.

■ How to Create a Stable Network Environment

 - Please change the time of your device to Korean time.

 - If you are using a VPN, please disconnect it before using the game.

 - Check your browser version and update it to the latest version.

 - If you're using a wireless network (Wi-Fi, hotspot, tethering, etc.) on your computer, please use it in an Ethernet environment.

 - If both wired and wireless Internet connections are enabled on your computer, please turn off the wireless Internet.

  ┗ Settings > Network & Internet > Change adapter options.

  ┗ Change Wireless Internet (Wi-Fi) to Disabled.