Password Sync: No Recent Syncronization

KB ID 0001640


I recently migrated the server that was running my Azure AD Connector. It was showing no errors post migration so I thought no more about it. A few days later I logged in to Office 365 and saw this;

password sync no recent syncronizations

AAD Connect Status
Azure AD Connect
Password sync: no recent synchronization


Apparently this can suddenly happen if you are running an old version of AAD Connect. But I checked and mine was brand new, (I’d only just installed it remember). A quick look in the Event Viewer pointed me in the right direction.

Event ID 611

Event ID 611

Log Name: Application
Source: Directory Synchronization
Date: xx/xx/xxxx xx:xx:xx
Event ID: 611
Task Category: None
Level: Error
Keywords: Classic
User: N/A
Computer: {server-name}
Password hash synchronization failed for domain:, domain controller hostname:, domain controller IP address: Details:
Microsoft.Online.PasswordSynchronization.DirectoryReplicationServices.DrsException: RPC Error 8453 : Replication access was denied. There was an error calling _IDL_DRSGetNCChanges.


I’ve highlighted the important part, RPC Error 8453: Replication access was denied. So we have a permissions/rights problem. As I’d set a new user up for the AAD connector software, I checked their rights and found out I was missing the following;

Ensure that the user you are running AAD sync under, has the following permissions on the ‘root’ of your local AD domain.

  • Replicating Directory Changes: Allow
  • Replicating Directory Changes All: Allow

AAD Replication User Rights

AAD Replication User Rights

Then I forced an AAD sync, and waited a few minutes, the problem then disappeared.

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Author: PeteLong

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1 Comment

  1. This is exactly what I was looking for, worked a treat, thank you Pete.

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