How to Fix Duplicate Exchange online Guid Errors in Office 365

These errors can generate a lot of issues, think about duplicate accounts or Mailusers  that are not removable.

Actually these issues are pretty easy to fix:

FIX:

(Get-MsolUser -UserPrincipalName affecteduser@domain.com).errors.errordetail.objecterrors.errorrecord| fl

#Search in EXO PowerShell for the object that is using the mentioned EXchangeGUID or ArchiveGUID:

Get-Recipient -IncludeSoftDeletedRecipients 'ExchangeGUID value'|ft RecipientType,PrimarySmtpAddress,*WhenSoftDeleted*

#Once you found the object that is using this ExchangeGUID or ArchiveGUID, you have to purge it:

#1. If it is a softdeleted MailUser:

Remove-MailUser ‘ExchangeGUID value' -PermanentlyDelete

#2. If it is a softdeleted UserMailbox, run:

Remove-Mailbox 'ExchangeGUID value' -PermanentlyDelete

#-if this command fails due to mailbox being protected by hold, you have to disable the hold first(check if data backup is required):

Set-Mailbox user@domain.com -LitigationHoldEnabled $false -InactiveMailbox

#3. If it turns to be an active mailuser/mailbox that is using this ExchangeGUID/ArchiveGUID, you need to evaluate the option to purge that user.

#4. After the faulty object has been purged from EXO, we need to fix the validation error by forcing the object provisioning:

Get-MsolUser -UserPrincipalName user@domain.com |fl *objectID*

Redo-MsolProvisionUser -ObjectId 'paste the *objectID* value from above command'

#5. Wait for 5 minutes and then run the next command, to confirm if your validation error is fixed:

(Get-MsolUser -UserPrincipalName user@domain.com).errors.errordetail.objecterrors.errorrecord| fl