Tested on 6.4.0.ER2 The issue is related to cross-site replication. Using client-server mode, it's currently not possible to specify custom name for backup cache (different from the name of the main cache), as "backup-for" setting is missing. The issue can be workarounded by using the same name for the main & backup cache.
Pedro Ruivo <pruivo> updated the status of jira ISPN-4874 to Coding In Progress
PR: https://github.com/infinispan/jdg/pull/312