One week out from Patch Tuesday and it’s been a bumpy release for the month, especially for older versions of Windows 10 and Server 2016. (Less affected: the consumer versions of Windows 10 2004 and 20H2.)
Windows Server 2016/1607 suffered the worst of the issues: the original version of the Servicing Stack update KB4601392 caused patching to get “stuck.” Server patchers had to jump through a ton of hoops to get the monthly security update installed. Microsoft pulled the bad update and replaced it with KB5001078. If you were unlucky and installed KB4601392 before it was pulled, Microsoft has this guidance to manually reset Windows updates components.