Microsoft's December 2025 security update has caused significant issues with Message Queuing (MSMQ) on older versions of Windows, including Windows 10 and Windows Server 2012 to 2019. After installing the update, MSMQ queues can become inactive, leading to errors such as "Insufficient resources to perform operation" when using Internet Information Services (IIS). Despite having sufficient disk space and memory, users receive misleading error messages due to changes in folder permissions related to the MSMQ security model. The root of the problem lies in the new requirement that MSMQ users have write access to the C:\Windows\System32\MSMQ\storage folder, a permission typically reserved for administrators. This change can disrupt clustered MSMQ environments under load and hinder the functionality of various applications reliant on message queuing. Microsoft has identified that the issue primarily affects enterprise or managed IT environments, with personal users on Windows Home or Pro editions likely to remain unaffected. For those experiencing issues, Microsoft recommends reaching out to their support team for potential workarounds. Some users have found success by uninstalling the update, though that would eliminate the associated security improvements. The problems underscore the ongoing challenges faced by enterprises that continue to use older operating systems, often postponing upgrades to avoid costs, which now appears increasingly risky.