rebalance failed with "gen_fsm,sync_send_event," error during online upgrade from 1.7.2 to 1.8.1 on windows ( workaround is to wait 30 seconds between add_node and starting the rebalance )

Install membase server 1.7.2r-20 on 4 nodes windows server 2008 R2 64bit and couchbase server 1.8.0-810 on one node.
Create 4 nodes cluster of membase server 1.7.2.
Load 1000000 items to default bucket.
Add node 200 with couchbase server 1.8.1-810 to cluster.
Rebalance. Failed
Try rebalance one more time. Complete rebalance.

Error in log page
Server error during processing: ["web request failed",
{path,"/controller/rebalance"},
{type,exit},
{what,
{noproc,
{gen_fsm,sync_send_event,
[{global,ns_orchestrator},
{start_rebalance,
['ns_1@10.3.121.182',
'ns_1@10.3.121.183',
'ns_1@10.3.121.201',
'ns_1@10.3.121.202',
'ns_1@10.3.121.200'],
[],[]}]}}},
{trace,
[{gen_fsm,sync_send_event,2},
{menelaus_web,do_handle_rebalance,3},
{menelaus_web,loop,3},
{mochiweb_http,headers,5},
{proc_lib,init_p_do_apply,3}]}]