Encountered an error while processing Active Directory attributes for a user. This error caused User Replication to abort ...

Encountered an error while processing Active Directory attributes for a user.  This error caused User Replication to abort synchronization of this domain.  Synchronization will be retried for this domain.

User: %1  AD Attribute: %2  Error: %3
Cause: This event occurs for a variety of reasons.  The most common are domain controllers going down, or the server running out of memory.
Resolution:
Check for failures in the domain infrastructure. Because the User Replicator automatically retries the operation, when the error is resolved, the User Replicator will automatically start synchronizing again.