Greetings, Rune Hunters.

First of all, we would like to sincerely apologize for the inconvenience caused to your gameplay due to the issue where UNDECEMBER did not operate correctly in certain Windows PC environments.

Currently, this issue has been solved.
The issue was caused by Windows Defender, the Windows firewall, mistaking UNDECEMBER as a malicious program during the update process, and we confirmed that this issue could occur from time to time when the firewall is updated.

Please update the Windows Defender and re-install the game if UNDECEMBER is still being mistaken as a malicious program when logging into the game.

※ If you continue to experience issues despite updating the Windows Defender and re-installing the game, please contact Support and we will make an effort to assist you as quickly as we can.
ㄴ Support: [Go to Support]

Once again, we would like to apologize to the Rune Hunters for the inconvenience this issue has caused.

Thank you.