Enable the disabled Online archive:
If the disabled archive still exists in the database, you can reconnect it to the primary mailbox. Solution: You can get the archive quid by searching the database with the following: Get-MailboxStatistics -Database Archive | Export-Csv c:\archivestat.csv Enable-mailbox -identity <alias of user> -ArchiveGUID <archiveMailboxGuid> -ArchiveDatabase <archiveDB> -Archive