Microsoft warns MSMQ may fail after December update
⚠️ Microsoft warns a December security update (KB5071546) can cause MSMQ to become inactive in enterprise and clustered environments, disrupting applications that rely on queued messaging. Reported symptoms include IIS failures with resource errors, applications unable to write to queues, and misleading log entries about disk space. Microsoft says a workaround exists but directs admins to contact Support for Business; community responders have recommended temporarily granting write access to C:\Windows\System32\msmq or rolling back the update until an official fix is issued. Affected systems include Windows Server 2012/2012 R2/2016/2019 and several Windows 10 builds.
