elasticsearch _ x-pack

[2018-10-12T16:54:29,184][WARN ][o.e.x.m.e.l.LocalExporter] unexpected error while indexing monitoring document
org.elasticsearch.xpack.monitoring.exporter.ExportException: [.monitoring-es-6-2018.10.12/GVtSVei7TbKtd2C-wKuIuQ] IndexClosedException[closed]
at org.elasticsearch.xpack.monitoring.exporter.local.LocalBulk.lambda$throwExportException$2(LocalBulk.java:140) ~[?:?]
at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193) ~[?:1.8.0_131]