Received message from unsupported version: [2.0.0] minimal compatible version is: [5.0.0]

java.lang.IllegalStateException: Received message from unsupported version: [2.0.0] minimal compatible version is: [5.0.0]
        at org.elasticsearch.transport.TcpTransport.messageReceived(TcpTransport.java:1379) ~[elasticsearch-5.5.2.jar:5.5.2]
        at org.elasticsearch.transport.netty4.Netty4MessageChannelHandler.channelRead(Netty4MessageChannelHandler.java:74) ~[transport-netty4-5.5.2.jar:5.5.2]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [netty-transport-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [netty-transport-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [netty-transport-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:310) [netty-codec-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:297) [netty-codec-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:413) [netty-codec-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:265) [netty-codec-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [netty-transport-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [netty-transport-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [netty-transport-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86) [netty-transport-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [netty-transport-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [netty-transport-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) [netty-transport-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1334) [netty-transport-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) [netty-transport-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) [netty-transport-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:926) [netty-transport-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:134) [netty-transport-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:644) [netty-transport-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.channel.nio.NioEventLoop.processSelectedKeysPlain(NioEventLoop.java:544) [netty-transport-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:498) [netty-transport-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:458) [netty-transport-4.1.11.Final.jar:4.1.11.Final]
        at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858) [netty-common-4.1.11.Final.jar:4.1.11.Final]
        at java.lang.Thread.run(Thread.java:745) [?:1.8.0_25]
[2017-09-16T22:38:18,934][WARN ][o.e.t.n.Netty4Transport  ] [mmRuckB] exception caught on transport layer [[id: 0x7d2300b5, L:/127.0.0.1:9300 - R:/127.0.0.1:25350]], closing connection网上说版本的问题，但是都说不清，如何去升级版本呢？我的es已经是5.5.2了呀！