Greetings, Rune Hunters. Certain Rune Hunters are experiencing an issue where UNDECEMBER does not operate on PC. First of all, we would like to apologize for the inconvenience caused by the game suddenly crashing. The Windows Defender Firewall is mistaking UNDECEMBER as a malicious program during the update process in Windows. We are currently checking this issue. UNDECEMBER does not cause abnormalities in your PCs, so please rest assured. This issue can be solved by adding UNDECEMBER to the list of apps that are allowed by the Windows Defender Firewall. Please see the steps below for more information. [b]How to Solve the Game Crashing Issue in Certain PC Conditions[/b] * Refer to the Microsoft Support link: [Add an app to the list of allowed apps] * [Start] > [Control Panel] > [System and Security] > [Windows Defender Firewall] > [Allow an app or feature through Windows Defender Firewall] > [Allow apps to communicate through Windows Defender Firewall] > [Change Settings] > Add UNDECEMBER to 'Allowed apps and features' * [Start] > Windows [Settings] > [Update & Security] > [Windows Security] > [Firewall & network protection] > [Allow an app through firewall] > [Allow apps to communicate through Windows Defender Firewall] > Add UNDECEMBER to 'Allowed apps and features' ※ If UNDECEMBER cannot be found in the list of [Allowed apps and features], select [Allow another app] and add UNDECEMBER through the path that it is installed in. We would like to remind you once again that UNDECEMBER does not cause abnormalities in your PCs. We will make an effort to solve this issue as quickly as possible. Thank you.