https://www.bleepingcomputer.com/news/microsoft/microsoft-pulls-windows-kb4601392-for-blocking-security-updates/

Microsoft has pulled a problematic Windows servicing stack update (SSU) after blocking Windows 10 and Windows Server customers from installing the security updates released during this month Patch Tuesday.

Servicing stack updates are designed to provide fixes to the Windows servicing stack, the component used by the OS to correctly receive and install updates.