Microsoft has released an out-of-band update to fix a Message Queuing (MSMQ) issue that arose after the December 2025 update. This patch is available for several Windows versions, including Windows 10 22H2 ESU, Windows 10 Enterprise LTSC 2021, and Windows 10 LTSB 2016, as well as various Windows Server versions from 2008 to 2019. The issue primarily impacted enterprise environments, while users on Pro and Home editions were "very unlikely" to experience it. The root cause was a change requiring MSMQ to have write access to areas typically restricted, leading to message queuing disruptions and misleading error logs. Microsoft documented the known issue on December 12, 2025, after several days of recognition, during which administrators had to implement workarounds. The update addresses the problem but raises concerns about Microsoft's quality assurance practices, especially given MSMQ's importance in corporate infrastructures. Users expressed dissatisfaction due to service disruptions caused by the issue.