ealsticsearch安装ik插件，建索引时报下面的错误，啥原因呢？

Exception in thread "main" java.lang.IllegalArgumentException: Unknown Analyzer type [org.elasticsearch.index.analysis.IkAnalyzerProvider] for [ik]

	at org.elasticsearch.index.analysis.AnalysisModule.configure(AnalysisModule.java:320)

	at org.elasticsearch.common.inject.AbstractModule.configure(AbstractModule.java:61)

	at org.elasticsearch.common.inject.spi.Elements$RecordingBinder.install(Elements.java:233)

	at org.elasticsearch.common.inject.spi.Elements.getElements(Elements.java:105)

	at org.elasticsearch.common.inject.InjectorShell$Builder.build(InjectorShell.java:143)

	at org.elasticsearch.common.inject.InjectorBuilder.build(InjectorBuilder.java:99)

	at org.elasticsearch.common.inject.InjectorImpl.createChildInjector(InjectorImpl.java:159)

	at org.elasticsearch.common.inject.ModulesBuilder.createChildInjector(ModulesBuilder.java:55)

	at org.elasticsearch.indices.IndicesService.createIndex(IndicesService.java:358)

	at org.elasticsearch.cluster.metadata.MetaDataCreateIndexService$2.execute(MetaDataCreateIndexService.java:358)

	at org.elasticsearch.cluster.service.InternalClusterService$UpdateTask.run(InternalClusterService.java:388)

	at org.elasticsearch.common.util.concurrent.PrioritizedEsThreadPoolExecutor$TieBreakingPrioritizedRunnable.runAndClean(PrioritizedEsThreadPoolExecutor.java:231)

	at org.elasticsearch.common.util.concurrent.PrioritizedEsThreadPoolExecutor$TieBreakingPrioritizedRunnable.run(PrioritizedEsThreadPoolExecutor.java:194)

	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)

	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)

	at java.lang.Thread.run(Thread.java:745)