Microsoft has released manual mitigation steps for IT administrators dealing with a known Windows Server Update Services (WSUS) issue that causes Windows Update scans to fail or time out. The problem affects both client platforms (Windows 10, version 1607 and later) and server platforms (Windows Server 2012 and later).

On affected WSUS servers, administrators have been unable to deploy the latest Windows updates through WSUS or Configuration Manager. Microsoft traced the problem to a buildup of publishing metadata that increases synchronization times or causes sync operations to time out entirely.

Impact escalated starting July 13, prompting Microsoft to roll out a service-side mitigation the following Saturday. According to Microsoft, that fix restored normal synchronization behavior, but only for newly installed or rebuilt WSUS servers.

For organizations running existing WSUS installations that are still experiencing long sync times, Microsoft published manual cleanup guidance on Monday via the Windows release health dashboard. The company said the unneeded metadata present in existing installations can be safely removed.

Recommended cleanup steps

  • Back up each SUSDB database before making changes
  • Run a cleanup query from SQL Management Studio against all SUSDB databases, including WSUS replicas
  • Update the MaxXMLPerRequest value back to its default setting
  • Reindex SUSDB after cleanup
  • Run the WSUS Server Cleanup Wizard
  • Run IISReset or recycle the WsusPool application pool to clear cached catalog state

Microsoft warned that the first Windows Update scan following cleanup may take longer than usual, but subsequent scans should return to normal timing. It also noted that the client-side DataStore.edb file will not shrink automatically after detectoids are removed, and that this behavior is expected and does not affect scan performance.

This is not the first time WSUS sync problems have disrupted update deployment. Microsoft addressed similar issues preventing admins from delivering the latest Windows updates in May 2025, July 2025, and August 2025.

Administrators still experiencing degraded WSUS performance should follow the manual cleanup process rather than waiting for the issue to resolve on its own, since the server-side mitigation only applies to new or rebuilt installations.