mailboxes failing to backup since 7.7 upgrade in Exchange Server Add-On Support Posted December 23, 2009 · Report reply I am having a similar issue although I do not get a specific error message. After upgrading to v7.7 (with the latest v188.8.131.52 driver fix), I just see the "Exchange Mailboxes" group but no individual mailboxes. As a test, I un-installed v7.7 and re-installed v7.6 and I could see all the mailboxes again with no other settings changes. I was using the v7.7 client in both cases. I am guessing it is another bug. I'll have to follow-up with tech support unless there are any solutions already out there.