FRS cannot find the DNS name for a replication partner.
Verify that DNS is working correctly and that this system is able to resolve the DNS names of its replication partners. Check general network connectivity and ensure there are no firewalls between the members. For more details about this error, look at the text for event ID 13525 in the File Replication Service event log on this system and look for DsCrackNames failures in the FRS debug logs on this member.