Encountered an unrecognized error while processing users from a domain. This error caused User Replicator to abort synchronization ...

Encountered an unrecognized error while processing users from a domain. This error caused User Replicator to abort synchronization of this domain.  Synchronization will be retried for this domain.  If this domain is not enabled for Lync Server, then this error can be ignored.

Domain: %1 (DN: %2) Error: %3 (%4)
Cause: The cause for this error can vary. Please review the errors listed above.
Resolution:
Contact support services if the error is not descriptive enough to remedy the problem.