December 2025 Windows Security Update Breaks Message Queuing (MSMQ) in Enterprise Environments

Microsoft’s latest Windows security update is causing unexpected headaches for enterprise administrators. The company has confirmed that the December 2025 security patch disables Message Queuing (MSMQ) on some Windows 10 systems and older Windows Server versions, which leads to application and service failures.

Message Queuing (MSMQ) in Windows is a messaging protocol that enables applications running on different systems or at different times to communicate reliably through queues. It works by storing messages in a queue until the receiving application is ready to process them, which ensures delivery even if the network or the destination system is temporarily unavailable. MSMQ is commonly used in distributed systems to decouple components, improve scalability, and maintain data integrity during asynchronous communication.

What are the symptoms reported by affected Windows systems?

On the Windows Release Health dashboard, Microsoft warned that some users may encounter Message Queuing (MSMQ) failures, particularly in clustered environments under heavy load. The problems include MSMQ queues becoming inactive, IIS sites showing “Insufficient resources to perform operation” errors, and applications failing to write to queues.

According to Microsoft, some users might experience that attempts to create message files fail due to permission issues. Moreover, misleading error logs suggest insufficient disk space or memory, even though system resources are adequate, which makes troubleshooting more difficult.

“This issue is caused by the recent changes introduced to the MSMQ security model and NTFS permissions on C:\Windows\System32\MSMQ\storage folder. MSMQ users now require write access to this folder, which is normally restricted to administrators. As a result, attempts to send messages via MSMQ APIs might fail with resource errors,” Microsoft explained.

Affected Windows versions and enterprise environments

This message queuing bug impacts users who installed the security update (KB5071546) on Windows 10 22H2 and earlier (up to 1607), as well as Windows Server 2012 to 2019. It primarily affects enterprise or managed IT environments, and Windows 10 Home and Pro devices are unlikely to encounter this issue.

Microsoft is currently investigating this bug, but there is no ETA on when a fix will be available for affected customers. For now, the company advises affected organizations to reach out to its support team for an official workaround. Some users have found that uninstalling the update resolves the issue, but doing so also removes the security improvements included in the security patch.

Windows 10 has officially reached the end of support, which means no more free security updates or feature improvements. For organizations that need extra time to migrate, Microsoft offers the Windows 10 Extended Security Updates (ESU) program, which provides critical security patches for up to three additional years on a paid basis. This option allows businesses to maintain security while planning their transition to Windows 11 or other supported platforms.