Seen [0] on RelEng first time with module-based shard (tell-based protocol).
Member-3 was the old leader, member-2 became new leader.

This is similar to CONTROLLER-1693 in that member-2 has seen UnreachableMember after remove-shard-replica.
This is also similar to CONTROLLER-1705 in that the client (at member-3) has not properly reconnected to the new leader.

The quoted part of the title is seen in member-3 karaf.log [1]:
2017-06-08 07:26:38,108 | INFO | lt-dispatcher-29 | aftActorLeadershipTransferCohort | 193 - org.opendaylight.controller.sal-akka-raft - 1.5.1.Carbon | member-3-shard-default-config: Successfully transferred leadership to null in 3.074 s

[0] https://logs.opendaylight.org/releng/jenkins092/controller-csit-3node-clustering-only-carbon/736/log.html.gz#s1-s20-t1-k2-k9
[1] https://logs.opendaylight.org/releng/jenkins092/controller-csit-3node-clustering-only-carbon/736/odl3_karaf.log.gz