Active Directory Sync Issues in Windows Server 2025

Timeline

1. 20.10.2025 18:27 1 articles · 23h ago

   Microsoft Fixes Active Directory Sync Issues in Windows Server 2025

   Microsoft has released a fix for Active Directory synchronization issues affecting Windows Server 2025 systems. The problem occurs after installing security updates released since September 2025. It impacts synchronization for large Active Directory security groups exceeding 10,000 members, particularly when using Microsoft Entra Connect Sync. A Known Issue Rollback (KIR) Group Policy is available for managed devices, and a registry key workaround is provided for non-managed devices and home users. A separate bug causing Windows update failures on Windows 11 24H2 and Windows Server 2025 devices is also being addressed. Guidance has been issued for smart card authentication issues across all supported Windows versions.

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   • Microsoft fixes Windows Server Active Directory sync issues — www.bleepingcomputer.com — 20.10.2025 18:27

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Information Snippets

• The issue affects Active Directory Domain Services (AD DS) synchronization, specifically Microsoft Entra Connect Sync.

  First reported: 20.10.2025 18:27
  1 source, 1 article
  Show sources

  • Microsoft fixes Windows Server Active Directory sync issues — www.bleepingcomputer.com — 20.10.2025 18:27

• The problem arises after installing the September 2025 Windows security update (KB5065426) or later updates.

  First reported: 20.10.2025 18:27
  1 source, 1 article
  Show sources

  • Microsoft fixes Windows Server Active Directory sync issues — www.bleepingcomputer.com — 20.10.2025 18:27

• The bug impacts synchronization of large AD security groups exceeding 10,000 members.

  First reported: 20.10.2025 18:27
  1 source, 1 article
  Show sources

  • Microsoft fixes Windows Server Active Directory sync issues — www.bleepingcomputer.com — 20.10.2025 18:27

• Microsoft has provided a Known Issue Rollback (KIR) Group Policy for managed devices.

  First reported: 20.10.2025 18:27
  1 source, 1 article
  Show sources

  • Microsoft fixes Windows Server Active Directory sync issues — www.bleepingcomputer.com — 20.10.2025 18:27

• A registry key workaround is available for non-managed devices and home users.

  First reported: 20.10.2025 18:27
  1 source, 1 article
  Show sources

  • Microsoft fixes Windows Server Active Directory sync issues — www.bleepingcomputer.com — 20.10.2025 18:27

• A separate bug causing Windows update failures on Windows 11 24H2 and Windows Server 2025 devices is being addressed.

  First reported: 20.10.2025 18:27
  1 source, 1 article
  Show sources

  • Microsoft fixes Windows Server Active Directory sync issues — www.bleepingcomputer.com — 20.10.2025 18:27

• Guidance has been issued for smart card authentication issues across all supported Windows versions.

  First reported: 20.10.2025 18:27
  1 source, 1 article
  Show sources

  • Microsoft fixes Windows Server Active Directory sync issues — www.bleepingcomputer.com — 20.10.2025 18:27