Microsoft releases out-of-band fix for Windows Server sign-in bug

Microsoft has released an out-of-band patch for Windows Server to address an issue that may prevent remote desktop users from connecting to the system.

The flaw causes performance issues with Windows Server, which would result in either a sluggish login process, general slowness, or at worst a black screen, Microsoft said.

Windows Server 2019 is at risk and Microsoft has released KB5010196 to address this issue. The bug also affects Windows Server 2012 Release 2, which the company fixed with KB5010215.

Windows Server 2022 and 2016 are also affected, which the company said it would address in the coming days.

The bug stemmed from update KB5008218 that Microsoft released during a regular update on Patch Tuesday on December 14. This update introduced security changes for Windows.

Out-of-band updates will not automatically install as part of the Windows Update service, which means administrators must install them manually by importing them into Windows Server Update Service (WSUS). They can get the Windows Server 2019 patch by visiting the Microsoft Update Catalog website. Windows Server 2012 Release 2 users can go here.

The latest updates are cumulative and the Windows Server 2019 update inherits three other less pressing Windows issues identified by Microsoft. This includes errors for devices using Asian language packs and a temporary issue starting the Windows Cluster service that disappears on restart after about 20 minutes. There is also an issue with versions of Windows Server used as Key Management Services hosts that may prevent certain Windows 10 client operating systems from being activated. The company will fix them in future releases, he said.

Out of band patches for Windows Server are rare. Microsoft released one in November last year, fixing a bug in Windows Server when used as a domain controller. The flaw prevented servers from authenticating legitimate users attempting to access resources using a single sign-on token.