Skip to main content

Error

Installing Exchange 2010 Service Pack 1 Fails At Mailbox Role: Database is mandatory on UserMailbox.

In a recent incident, an Exchange server had a complete volume failure during testing. Exchange 2010 was reinstalled but when installing Service Pack 1, it failed upgrading the Mailbox Role. Upon reviewing the log, I found the following line: Database is mandatory on UserMailbox. Property Name: Database The error doesn’t explain the problem very well but it is basically saying that there is a UserMailbox without a database, which should never happen. The failure of the volume and subsequent reinstall of 2010 left the arbitration mailboxes (and one or two user mailboxes) orphaned. Most of the suggestions to resolve this problem list doing things like deleting the system mailboxes and running “setup.com /PrepareAD”. After looking around, I was able to parse together a few other options and find a fix.