Active Directory property ‎’homeMDB‎’ is Not Writeable [Fixed]

Error: MigrationPermanentException: Active Directory property ‎’homeMDB‎’ is not writeable on the recipient for a particular mailbox. This could be one of the errors you may face while migrating your on-premise Exchange server mailboxes to Office 365. Also, you may face this issue while moving from the old Exchange to the new version internally. Recently, I encountered a similar situation in the Hybrid Exchange setup with Exchange 2007 and Office 365. Surprisingly, this error appeared for specific users only.

The main reason for this error is the permission of a particular user account in the domain. The wrong or missing user permission of the particular account is stopping the Exchange command from moving the mailbox from on-premise Exchange servers to Office 365 online.  Here is how to solve this error and migrate the affected user mailboxes.

The Solution

We need to enable the permission inheritance for the particular Active Directory account.

1) To enable the required security permission for the AD user, we must see the security tab in the Active Directory users list.  Open Active Directory users and computers on your domain controller and change the view to Advanced Features as below.

Now you should see the security tab for the users and computers objects.

2) Open the user account, which gives the error while migrating to Office 365.

Under the ‘Security’ tab (this will be visible when you enable Advanced View as mentioned in step 1), click on the ‘Advanced’ button.  Mostly, the inheritance permission for this user would be disabled. Enabling this permission will solve the issue, click on ‘Enable inheritance’ button and apply the changes.

3) In a hybrid setup, you should sync this local AD change of user account to Office 365 through Azure AD Connect.  Either you can wait for the scheduled sync or execute the delta sync manually by the following command on the server where the Azure AD sync tool is installed.

Start-ADSyncSyncCycle -PolicyType Delta

Once this change is synchronized to Office 365, you can migrate the mailbox from the on-premise Exchange server to Office 365 online without the Active Directory property ‎’homeMDB‎’ error.

If you are doing this setup for internal mailbox migration, you should be able to do it with the earlier user account inheritance security changes. The Azure AD connect option is only for the hybrid Exchange server setup.