When running an Active Directory synchronization you receive the following message:
The directory is being synchronized by another user
Known to apply to the following Sophos product(s) and version(s)
SafeGuard Management Center
What To Do
You must cancel the Active Directory synchronization which was started during another session on a separate SafeGuard Management Center or with a synchronization script.
To do this, go to the "Options" section of the Management Center, and click 'Reset import flag'.