Cannot restore automatically deleted mailbox - Uniqueness violation. Property: OnPremiseSecurityIdentifier RRS feed

  • Question

  • I have a local AD user and she has two email addresses. Yesterday, this user was synced to Azure AD with the email address user@domainABC.com. However, I found out that this user needed to be synced to Azure AD with a different email address which is user@domain123.com. So I updated my user in local AD to point to this other email address instead and this is where the problems started. 

    I noticed today that there was a syncing issue on Azure AD Connect with the user. I clicked the option for the syncing issue to be fixed automatically. This then deleted the mailbox user@domainABC.com. My plan was to the just restore this as a regular mailbox that wasn't synced with Azure AD Connect. This is the email address I am now unable to restore from deleted users.

    Further to this, user@domain123.com should be directory synced to the local AD user but this does not come up as directory synced in Azure BUT password hash sync is working for this user.

    So the problem seems to have started when I tried to update the syncing email address and now I believe there are some conflicts which are stopping things from working. 

    I tried to restore the user on Powershell and got this error: 

    Restore-MsolUser : Uniqueness violation. Property: OnPremiseSecurityIdentifier. At line:1 char:1 + Restore-MsolUser -OBjectId 00f460d25ef941479eaa10832e0379d4 -AutoReco ... + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : OperationStopped: (:) [Restore-MsolUser], MicrosoftOnlineException + FullyQualifiedErrorId : Microsoft.Online.Administration.Automation.UniquenessValidationException,Microsoft.Onlin e.Administration.Automation.RestoreUser

    Can anyone advise what I can try next? I really need to restore this user ASAP. 
    • Moved by Dave PatrickMVP Thursday, November 12, 2020 1:01 PM looking for forum
    Thursday, November 12, 2020 11:17 AM