Microsoft yesterday began advising organizations running Windows 10 version 1809 PCs and Windows Server 2019 against installing the update KB4520062.
Microsoft released it on October 15 for 1809 along with other versions of Windows 10 as the second update following the October Patch Tuesday update. It is a non-security and optional update.
The reason it's advising customers not to install the update is that Microsoft Defender ATP security tools "might stop running and might fail to send reporting data".
Windows 10 Pro (64-bit), Panda DOME 18.7.4, MBAM3 Pro, Windows Firewall, OpenDNS Family Shield, SpywareBlaster, MVPS HOSTS file, MBAE Premium, MCShield, WinPatrol PLUS, SAS (on-demand scanner), Zemana AntiLogger Free, Microsoft EDGE, Firefox, Pale Moon, uBlock Origin, CryptoPrevent.
[I believe computer-users who sandbox (Sandboxie) are acting prudently.]