Active Directory schema extension issue if you use a Windows Server 2025 schema master role

Microsoft

Oct 09, 2025

Working with our Windows Team counterparts we have become aware of a specific set of circumstances that might affect your on-premises Active Directory environment replication after you install a rece...

Published Oct 09, 2025

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Microsoft

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Exchange Team Blog

You Had Me at EHLO.

bbzome

Brass Contributor

Oct 10, 2025

Well... i've upgrade to Exchange SE and later upgraded DC's to 2025.
I'm not running into AD replication issues (yet), but i'm stuck because AD and Forest functional levels were upgrade to 2025.
What happens if SE CU1 comes out before Windows fix?

Nino_Bilic
Microsoft
Oct 16, 2025
This will not happen, no. The fix will arrive before ESE CU1.

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Active Directory schema extension issue if you use a Windows Server 2025 schema master role