Error while moving some partitions to OnlinePartition state

[chenlax]

first,i increase some partitions for a topic,and is ok,
then i do kafka-reassign-partitions.sh ,and it speed long times to replicated 
data,
and a partition status as "partition: 68   leader: 5       replicas: 8,0,5,1    
   isr: 5,1"
so i do kafka-preferred-replica-election.sh & kafka-reassign-partitions.sh,then 
i find the partitions are decrease,the partition nums turn back to i do 
increase operation. 
what could cause this? and how i can recover to increase  partitions.

log as follow:

ERROR [Partition state machine on Controller 0]: Error while moving some 
partitions to OnlinePartition state (kafka.
controller.PartitionStateMachine)
kafka.common.StateChangeFailedException: Controller 0 epoch 16 initiated state 
change for partition [Topic_1,85] to OnlinePartition fai
led because the partition state machine has not started
        at 
kafka.controller.PartitionStateMachine.kafka$controller$PartitionStateMachine$$handleStateChange(PartitionStateMachine.scala:162)
        at 
kafka.controller.PartitionStateMachine$$anonfun$handleStateChanges$2.apply(PartitionStateMachine.scala:125)
        at 
kafka.controller.PartitionStateMachine$$anonfun$handleStateChanges$2.apply(PartitionStateMachine.scala:124)
        at 
scala.collection.immutable.HashSet$HashSet1.foreach(HashSet.scala:130)
        at 
scala.collection.immutable.HashSet$HashTrieSet.foreach(HashSet.scala:275)
        at 
scala.collection.immutable.HashSet$HashTrieSet.foreach(HashSet.scala:275)
        at 
scala.collection.immutable.HashSet$HashTrieSet.foreach(HashSet.scala:275)
        at 
kafka.controller.PartitionStateMachine.handleStateChanges(PartitionStateMachine.scala:124)
        at 
kafka.controller.KafkaController.onPreferredReplicaElection(KafkaController.scala:618)
        at 
kafka.controller.PreferredReplicaElectionListener$$anonfun$handleDataChange$2.apply$mcV$sp(KafkaController.scala:1265)
        at 
kafka.controller.PreferredReplicaElectionListener$$anonfun$handleDataChange$2.apply(KafkaController.scala:1253)
at 
kafka.controller.PreferredReplicaElectionListener$$anonfun$handleDataChange$2.apply(KafkaController.scala:1253)
        at kafka.utils.Utils$.inLock(Utils.scala:538)
        at 
kafka.controller.PreferredReplicaElectionListener.handleDataChange(KafkaController.scala:1253)
        at org.I0Itec.zkclient.ZkClient$6.run(ZkClient.java:547)
        at org.I0Itec.zkclient.ZkEventThread.run(ZkEventThread.java:71)


Thanks，
Lax