ALTER DATABASE failed because a lock could not be placed on database
In general, this means that there were multiple connections to ApexSQL Audit Central Repository when archiving started. With more than one connection active, 'lock' cannot be enforced and causes the fail. These multiple connections can be either multiple ApexSQL Audit GUI running at the time of archive, or a scheduled/ongoing reporting job that would be reading from the repository at the same time as archiving.
