Failed to update the list of domains in this forest to synchronize. This failure occurred because DsGetDcName failed to provide ...

Failed to update the list of domains in this forest to synchronize.  This failure occurred because DsGetDcName failed to provide any valid domain controllers to connect to.  User Replicator has a list from a previous cycle, and will continue to use the old list.  DsGetDcName failures usually stop occurring after some amount of time.  If this error continues to occur, the computer should be rebooted to fix the NetLogon service which calls DsGetDcName.