Microsoft Releases Out-of-Band Update to Fix MSMQ Issue Caused by December 2025 Patch
January 2, 2026
Microsoft has promptly issued an out-of-band (OOB) update to address a critical Message Queuing (MSMQ) problem introduced in the December 2025 update. This emergency patch targets multiple Windows versions and aims to restore proper MSMQ functionality affected by recent updates.
Details of the Update
The fix is available for:
- Windows 10 22H2 ESU
- Windows 10 Enterprise LTSC 2021
- Windows 10 LTSB 2016
- Windows Server editions from 2008 to 2019
These patches incorporate the fixes from the original December 9, 2025 update but prevent MSMQ from entering a broken state, thus restoring its operation.
Impacted Environments and Symptoms
While primarily affecting enterprise environments, the issue was caused by a change requiring MSMQ to have write access to restricted areas. This alteration resulted in:
- MSMQ service failures
- Disruption of services like Internet Information Services (IIS)
- Applications unable to write to message queues
- Erroneous logs with messages such as “There is insufficient disk space or memory,” despite resources being sufficient
Microsoft noted that users on Windows Pro and Home editions were "very unlikely" to encounter this issue.
Timeline and Resolution
The problem was acknowledged by Microsoft on December 12, 2025, after a few days of affecting enterprise systems. During this period, administrators employed workarounds such as adjusting folder permissions or rolling back the problematic update.
The new OOB update effectively resolves the MSMQ issue, but it has reignited concerns about quality control, especially considering MSMQ's long history and continued relevance in legacy enterprise applications.
Importance of MSMQ in Enterprise IT
MSMQ has been a staple in Windows environments since the days of Windows 95 and NT 4. Its robustness and support make it vital for legacy systems where direct connectivity options are limited. Despite newer cloud-based messaging alternatives, many organizations depend on MSMQ for reliable communication between applications.
Industry Response and Reflection
Affected users experienced significant disruptions, with many having to manage customer complaints as critical services failed. Microsoft’s quick response has been commended; however, the incident exposes potential gaps in testing and validation processes, especially given MSMQ’s longstanding presence in enterprise ecosystems.
While MSMQ is not a new technology, its failure highlights the importance of rigorous update validation, particularly for components integral to enterprise operations.
Note: Organizations should ensure they apply the latest OOB update promptly to mitigate ongoing risks and maintain operational stability.