GPMC error for "Security Options" after Updates 2020-09 in Windows Server 2016 Domain Controllers

Question

We have found that if a Windows Server 2016 DC has been patched with the current Cumulative Update 2020-09 and Servicing Stack Update 2020-09, the "Security Options" in a policy can no longer be opened in the GPMC afterwards. It is not clear which of these two updates really causes this. Windows Server 2019 DCs seem not to be affected.

Answer 1

Hello,

Microsoft had released the new KB4580346 to fix this issue. This release addresses an issue that might prevent you from accessing the Security Options data view in the Group Policy Management Editor (gpedit.msc) or Local Security Policy Editor (secpol.msc). The error is, "MMC has detected an error in a snap-in”.

https://support.microsoft.com/en-us/help/4580346/windows-10-update-kb4580346

Thanks.

Best regards,
Hannah Xiong

Answer 2

I've got this on DCs but also on at least one member server with the AD Tools installed

On that member server no admin tool which uses mmc.exe would launch.

I got "This app has been blocked for your protection" until I deleted the registry key and restarted

Answer 3

HI All,

I have applied new KB4580346 but it did not resolve the problem. Error "MMC has detected an error in a snap-in” still appearing.