Quote:Microsoft resolved a known issue causing Microsoft Defender Advanced Threat Protection (ATP) to stop running and fail to send reporting data on some Windows devices after installing the KB4520062 optional non-security update.
 
Some Windows 10 customers affected by the now-fixed bug also received 0xc0000409 errors in the Event Viewer on MsSense.exe according to the known issue's entry.
 
The optional non-security KB4520062 update behind the issue was released on October 15 and it was designed to fix a problem leading to black screens being displayed during startup on the first sign in after installing updates.
 
The issue was acknowledged by Redmond on October 17, 2019, and it was described as impacting Microsoft Defender ATP on both client and server Windows versions were the Windows 10 October 2018 Update was installed.
 
The full list of affected platforms includes Windows 10 version 1809, Windows 10 Enterprise LTSC 2019, Windows Server version 1809, and Windows Server 2019 platforms.
 
As Microsoft noted on the issue's Windows 10 Health Dashboard entry, the consumer-grade Microsoft Windows Defender Antivirus was not affected by this bug.
 
The company addressed the Microsoft Defender ATP issue in the KB4523205 cumulative update released yesterday, as part of the November 2019 Patch Tuesday.