Windows 10 1607 and Windows Server 2016 users are experiencing errors when opening the the Security Options MMC in the group policy editor. Microsoft confirmed that the bug was introduced in September’s KB4577015 cumulative update. Remote administrators can bypass this bug by installing the Remote Administrative tools on Windows 10 v1709 and later and remotely edit the policy. The Remote Administrative Tools feature can be installed on any version of Windows 10 that is not available on the current version of the operating system and is required to be installed by default.
Source: https://www.bleepingcomputer.com/news/microsoft/microsoft-confirms-group-policy-editor-bug-in-windows-server-2016/