Entra Connect Sync: upgrade before 30 September 2026
Two weeks to go. If your Entra Connect Sync server isn't on version 2.5.79.0 or later by 30 September, synchronisation will stop. Not degrade — stop. And it stays stopped until you upgrade.
The reason: a back-end service change Microsoft shipped in May 2025 to harden the sync service. Older clients simply won't be able to talk to it.
What to do:
- Check your current version (Entra Connect Sync → About, or the Synchronization Service Manager)
- Upgrade to 2.6.84.0 — the current recommended release, which also carries security fixes. Don't just scrape the 2.5.79.0 minimum; you'll only be doing this again shortly.
- Grab the .msi from the Microsoft Entra admin center — it's the only place it's published now
- Confirm prerequisites first: .NET Framework 4.7.2 and TLS 1.2 enabled
If you're running a staging server, upgrade that first and verify before you touch production.