O365 Licence activation

I cannot activate a 365 licence on an end user and keep getting this message “Exchange: An unknown error has occurred. Refer to correlation ID.” I edited all attributes correctly so no idea what is going on. Did someone encounter a similar situation? How did you guys solve it?

Hi, I presume that you receive this message because you now have two archives, one online and one object on-prem and because of this the archive guid’s conflict. maybe try to fix this by doing several steps below:

  1. On the office 365 portal find the user and in the licenses section remove the ‘Exchange Online (plan 2)’ and save, once this is done run an AD Sync cycle from your AAD Sync server. (this will ensure no new mailboxes are created while you are fixing the current one).#

  2. Go onto your on-prem exchange server and open up the exchange management console, from here you need to find the user and right click ‘disable’ not ‘remove’.

  3. Now you recreate the mailbox in Exchange on-prem PowerShell, run the following commands:

A) Set-ADServerSettings -ViewEntireForest $True

B) Enable-RemoteMailbox “” -RemoteRoutingAddress “” -PrimarySMTPAddress “”

C) Set-RemoteMailbox “” -EmailAddressPolicyEnabled $True

D) Enable-RemoteMailbox “” -Archive

  1. Go back to your AAD Sync server and run a AD Sync cycle.

  2. Reapply the exchange license you removed earlier and wait for the new mailbox to create, you should notice that the errors disappear by this point however you aren’t done yet!

  3. Connect to Exchange Online Management Shell using a Global Admin or Exchange Online Administrator account. Now run the following command.

Get-Mailbox -softdeletedmailbox -identity example.user | exchangeguid

  1. Now you have the the guid of the disconnected mailbox you will need the one of the new mailbox, to get this simply input this command:

Get-Mailbox example.user | fl exchangeguid

  1. Now you have both the GUID’s that are ready to restore the mailbox using a mailbox restore request, to do this use the following command:

New-MailboxRestoreRequest -sourcemailbox -targetmailbox -AllowLegacydnMissmatch

  1. Now simply wait for the mailbox to restore.

Let me know the result…

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