I've got an interesting issue with a customer who is running Unity 5.0.1.  They recently made some upgrades around their network.  No changes were made to Exchange, it was only other MS servers.  After the changes were made they could no longer add or delete mailboxes from Unity.  I was there on Friday afternoon and I ran the permissions tool and it completed just fine, no errors.  I also applied all patches and ESs recommended for this sort of problem.  Nothing changed.  I have also double checked all the rights and permissions on the domain and in Exchange for the Unity accounts.  Everything looks right and still mailboxes cannot be added or deleted.

I am getting a number of errors when trying to delete or add a mailbox including-

Delete failed 0x80043307 (E_Notifier_User_Not_Monitored)

Delete Failed 0x08004480E (E_AV_DC_Domain_Needs_Resynch)

In Event Viewer-

AVDSAD cannot modify location object default in domain  (domain)

Has anyone seen anything like this before?  I am kind of suspecting the issue is somewhere on the Microsoft end, but I am not an MS expert.

Thanks in advance.

Justin