Microsoft has successfully addressed a significant issue affecting the Cluster service and virtual machine (VM) restarts following the installation of July’s Windows Server 2019 security updates. This resolution comes after the company acknowledged the bug in a private advisory three weeks ago, urging businesses to seek support to mitigate the cluster-related challenges.
Details of the Issue
In its earlier communication, Microsoft detailed that the Cluster service, a critical component for cluster operations, might malfunction after the installation of the KB5062557 update released on July 8th. This led to complications where certain nodes struggled to rejoin their clusters, particularly impacting systems with the BitLocker security feature enabled on Cluster Shared Volumes (CSV) drives. The company noted, “After installing the July Windows security update, the Cluster Service on Windows Server 2019 might repeatedly stop and restart, causing nodes to fail to rejoin the cluster or enter quarantine states, virtual machines to experience multiple restarts, and frequent Event ID 7031 errors within event logs.”
To assist organizations grappling with this issue, Microsoft encouraged reaching out to their Support for business for guidance on effective mitigation strategies.
Resolution and Updates
The recent August 2025 KB5063877 cumulative update for Windows Server 2019 has now rectified this known issue, alongside introducing other notable enhancements and bug fixes. For administrators looking to implement this update on affected systems, the process requires first deploying the KB5005112 servicing stack update, followed by the installation of KB5063877 through Windows Update, the Microsoft Update Catalog, or Windows Server Update Services (WSUS).
In addition to resolving the cluster service issue, Microsoft also tackled a widespread WSUS problem on Wednesday that hindered organizations from deploying the August 2025 KB5063878 cumulative update on Windows 11 24H2 devices. Furthermore, last month, the company addressed another WSUS bug that obstructed the deployment of the latest Windows updates due to synchronization issues with Microsoft Update.
Moreover, the cumulative updates from July 2024 rectified an issue stemming from the June 2025 security updates, which had caused the DHCP service to freeze on certain Windows Server systems.
As organizations navigate these updates, it is crucial to remain vigilant and proactive in managing their IT environments to ensure seamless operations and security compliance.
