Couchbase server auto restart and es server crashed

I am using Couchbase Server Version: 3.0.2-1603 Enterprise Edition (build-1603) + elasticsearch-transport-couchbase-2.1.1 + ES 1.5.2 . and I followed http://developer.couchbase.com/documentation/server/4.0/connectors/elasticsearch-2.1/elastic-intro.html to set up cb 2 es XDCR replication.
but wen I start replicateion, the couchbase server auto restart, and the ES server will crashed.
I don’t see any error in log.
and when I Pause the XDCR,the ES works fine.
can any body help?