2017-05-31T17:26:45.844+03:00 INFO  [ExtractorsResource] Added extractor <2ccf6d00-460d-11e7-b74d-fa163eee1616> of type [json] to input <5926ad96ff7c6701a91f6c76>.
2017-05-31T17:26:49.316+03:00 ERROR [BlockingBatchedESOutput] Unable to flush message buffer
java.lang.ClassCastException: Cannot cast java.lang.String to org.joda.time.DateTime
    at java.lang.Class.cast(Class.java:3369) ~[?:1.8.0_131]
    at org.graylog2.plugin.Message.getFieldAs(Message.java:379) ~[graylog.jar:?]
    at org.graylog2.plugin.Message.getTimestamp(Message.java:187) ~[graylog.jar:?]
    at org.graylog2.indexer.messages.Messages.propagateFailure(Messages.java:160) ~[graylog.jar:?]
    at org.graylog2.indexer.messages.Messages.bulkIndex(Messages.java:126) ~[graylog.jar:?]
    at org.graylog2.outputs.ElasticSearchOutput.writeMessageEntries(ElasticSearchOutput.java:105) ~[graylog.jar:?]
    at org.graylog2.outputs.BlockingBatchedESOutput.flush(BlockingBatchedESOutput.java:137) [graylog.jar:?]
    at org.graylog2.outputs.BlockingBatchedESOutput.forceFlushIfTimedout(BlockingBatchedESOutput.java:167) [graylog.jar:?]
    at org.graylog2.periodical.BatchedElasticSearchOutputFlushThread.doRun(BatchedElasticSearchOutputFlushThread.java:88) [graylog.jar:?]
    at org.graylog2.plugin.periodical.Periodical.run(Periodical.java:77) [graylog.jar:?]
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [?:1.8.0_131]
    at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) [?:1.8.0_131]
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180) [?:1.8.0_131]
    at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294) [?:1.8.0_131]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_131]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_131]
    at java.lang.Thread.run(Thread.java:748) [?:1.8.0_131]
2017-05-31T17:26:51.446+03:00 ERROR [BlockingBatchedESOutput] Unable to flush message buffer
java.lang.ClassCastException: Cannot cast java.lang.String to org.joda.time.DateTime
    at java.lang.Class.cast(Class.java:3369) ~[?:1.8.0_131]
    at org.graylog2.plugin.Message.getFieldAs(Message.java:379) ~[graylog.jar:?]
    at org.graylog2.plugin.Message.getTimestamp(Message.java:187) ~[graylog.jar:?]
    at org.graylog2.indexer.messages.Messages.propagateFailure(Messages.java:160) ~[graylog.jar:?]
    at org.graylog2.indexer.messages.Messages.bulkIndex(Messages.java:126) ~[graylog.jar:?]
    at org.graylog2.outputs.ElasticSearchOutput.writeMessageEntries(ElasticSearchOutput.java:105) ~[graylog.jar:?]
    at org.graylog2.outputs.BlockingBatchedESOutput.flush(BlockingBatchedESOutput.java:137) [graylog.jar:?]
    at org.graylog2.outputs.BlockingBatchedESOutput.forceFlushIfTimedout(BlockingBatchedESOutput.java:167) [graylog.jar:?]