I've been running a quite heavy kv workload and rebalancing kv nodes in and out (using 3.0.0). Not always, but sometimes I see an exception like:
So it seems that the SDK is not handling a state transition when nodes come and go properly (i.e. grabbing a new config and rescheduling the op transparently). Interestingly in the case above, the IP address was not one that I actually added or removed (10.143.194.101 was steady, in this case I added 10.143.194.102 in, but I've also seen it on rebalance out).