# Elasticsearch Cluster can't join new node **URL:** \ **Category:** Elasticsearch\ **Created:** [April 5, 2018, 3:40pm UTC](https://discuss.elastic.co/t/elasticsearch-cluster-cant-join-new-node/126964 "2018-04-05T15:40:45Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![souf\_el\_badraoui](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/souf_el_badraoui/32/47746_2.png) [@souf\_el\_badraoui](https://discuss.elastic.co/u/souf_el_badraoui)\ **Post date:** [April 5, 2018, 3:40pm UTC](https://discuss.elastic.co/t/elasticsearch-cluster-cant-join-new-node/126964/1 "2018-04-05T15:40:46Z")
i'm getting the below warn continuously after installing x-pack 6.2 failed to validate incoming join request from node org.elasticsearch.transport.RemoteTransportException: [internal:discovery/zen/join/validate] Caused by: java.lang.IllegalArgumentException: Unknown NamedWriteable [org.elasticsearch.cluster.metadata.MetaData$Custom][ml] at org.elasticsearch.common.io.stream.NamedWriteableRegistry.getReader(NamedWriteableRegistry.java:112) ~[elasticsearch-6.2.3.jar:6.2.3] at org.elasticsearch.common.io.stream.NamedWriteableAwareStreamInput.readNamedWriteable(NamedWriteableAwareStreamInput.java:45) ~[elasticsearch-6.2.3.jar:6.2.3] at org.elasticsearch.common.io.stream.NamedWriteableAwareStreamInput.readNamedWriteable(NamedWriteableAwareStreamInput.java:39) ~[elasticsearch-6.2.3.jar:6.2.3] at org.elasticsearch.cluster.metadata.MetaData.readFrom(MetaData.java:775) ~[elasticsearch-6.2.3.jar:6.2.3] at org.elasticsearch.cluster.ClusterState.readFrom(ClusterState.java:668) ~[elasticsearch-6.2.3.jar:6.2.3] at org.elasticsearch.discovery.zen.MembershipAction$ValidateJoinRequest.readFrom(MembershipAction.java:172) ~[elasticsearch-6.2.3.jar:6.2.3] at org.elasticsearch.common.io.stream.Streamable.lambda$newWriteableReader$0(Streamable.java:51) ~[elasticsearch-6.2.3.jar:6.2.3] at org.elasticsearch.transport.RequestHandlerRegistry.newRequest(RequestHandlerRegistry.java:56) ~[elasticsearch-6.2.3.jar:6.2.3] at org.elasticsearch.transport.TcpTransport.handleRequest(TcpTransport.java:1508) ~[elasticsearch-6.2.3.jar:6.2.3] at org.elasticsearch.transport.TcpTransport.messageReceived(TcpTransport.java:1382) ~[elasticsearch-6.2.3.jar:6.2.3] at org.elasticsearch.transport.netty4.Netty4MessageChannelHandler.channelRead(Netty4MessageChannelHandler.java:64) ~[?:?] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) ~[?:?] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) ~[?:?] at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) ~[?:?] at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:310) ~[?:?] at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:297) ~[?:?] at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:413) ~[?:?] at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:265) ~[?:?] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) ~[?:?] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) ~[?:?] at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) ~[?:?] at io.netty.handler.logging.LoggingHandler.channelRead(LoggingHandler.java:241) ~[?:?] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) ~[?:?] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) ~[?:?] at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:340) ~[?:?] at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1359) ~[?:?] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:362) ~[?:?] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:348) ~[?:?] at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:935) ~[?:?] at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:134) ~[?:?] at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:645) ~[?:?] at io.netty.channel.nio.NioEventLoop.processSelectedKeysPlain(NioEventLoop.java:545) ~[?:?] at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:499) ~[?:?] at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:459) ~[?:?] at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858) ~[?:?] at java.lang.Thread.run(Thread.java:748) [?:1.8.0\_161] Can you help with that please. ---
**Author:** ![dkyle](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/dkyle/32/59114_2.png) [@dkyle](https://discuss.elastic.co/u/dkyle)\ **Post date:** [April 5, 2018, 3:57pm UTC](https://discuss.elastic.co/t/elasticsearch-cluster-cant-join-new-node/126964/2 "2018-04-05T15:57:57Z")
Hi, > [@souf\_el\_badraoui](#): > > [org.elasticsearch.cluster.metadata.MetaData$Custom][ml] It looks like you have been using Machine Learning and one of the nodes in your cluster is having trouble reading the cluster state. X-Pack must be installed on every node in the cluster and you must also have `xpack.ml.enabled: true` set in the elasticsearch.yml file on every node ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [May 3, 2018, 3:58pm UTC](https://discuss.elastic.co/t/elasticsearch-cluster-cant-join-new-node/126964/3 "2018-05-03T15:58:19Z")
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