2018-04-20 08:54:38,943 INFO : org.graylog2.indexer.MongoIndexSet - Did not find a deflector alias. Setting one up now.
2018-04-20 08:54:38,951 INFO : org.graylog2.indexer.MongoIndexSet - There is no index target to point to. Creating one now.
2018-04-20 08:54:38,962 INFO : org.graylog2.indexer.MongoIndexSet - Cycling from <none> to <graylog_0>.
2018-04-20 08:54:38,966 INFO : org.graylog2.indexer.MongoIndexSet - Creating target index <graylog_0>.
2018-04-20 08:54:38,987 ERROR: org.graylog2.periodical.IndexRotationThread - Couldn't point deflector to a new index
org.graylog2.indexer.ElasticsearchException: Unable to create index template graylog-internal

Compressor detection can only be called on some xcontent bytes or compressed xcontent bytes