我安装的elasticsearch 是2.4.2,然后装了guard插件，启动的时候就报错

错误信息如下：Exception in thread "main" java.lang.IllegalStateException: Could not load plugin descriptor for existing plugin [search-guard-2.4.x]. Was the plugin built before 2.0?
Likely root cause: java.nio.file.NoSuchFileException: /usr/elasticsearch-2.4.2/plugins/search-guard-2.4.x/plugin-descriptor.properties
at sun.nio.fs.UnixException.translateToIOException(UnixException.java:86)
at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:102)
at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:107)
at sun.nio.fs.UnixFileSystemProvider.newByteChannel(UnixFileSystemProvider.java:214)
at java.nio.file.Files.newByteChannel(Files.java:361)
at java.nio.file.Files.newByteChannel(Files.java:407)
at java.nio.file.spi.FileSystemProvider.newInputStream(FileSystemProvider.java:384)
at java.nio.file.Files.newInputStream(Files.java:152)
at org.elasticsearch.plugins.PluginInfo.readFromProperties(PluginInfo.java:87)
at org.elasticsearch.plugins.PluginsService.getPluginBundles(PluginsService.java:378)
at org.elasticsearch.plugins.PluginsService.<init>(PluginsService.java:128)
at org.elasticsearch.node.Node.<init>(Node.java:158)
at org.elasticsearch.node.Node.<init>(Node.java:140)
at org.elasticsearch.node.NodeBuilder.build(NodeBuilder.java:143)
at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:194)
at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:286)
at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:35)
Refer to the log for complete error details