Windows Server · 2025 · Release · Out-of-band update
July 13, 2025—KB5064489 (OS Build 26100.4656) Out-of-band
- Release
- Cumulative update
- KB5064489 — Microsoft's article, opens in a new tab
Windows Server 2025: Current LTSC release
Microsoft's known issues — KB5064489
- Issue Known issue Active Directory domain controllers (DC) running on Windows Server 2025 and also running the schema master Flexible Single Master Operation (FSMO) role , will allow duplicate entries in attributes of schema objects. Commonly affected attributes include auxiliaryClass , possSuperiors , mayContain with values such as msExchBaseClass , msExchContainer , and msExchVirtualDirectoryFlags . When this occurs, Active Directory replication fails with a schema mismatch error, such as error 8418: The replication operation failed because of a schema mismatch between the servers involved." This issue can be observed when running Exchange Server setup forestprep and the schema master role for Active Direct Workaround: This issue is addressed KB5068861 .
Known issues — reported on the forum
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