I'm still very new at Elasticsearch. I am explicitly using the ArcSight Module with Logstash to populate my database and today I noticied that after update to 6.4.1 a field was missing in the index. I looked in management and index patterns (arcsight-*) and sourceUserName could not be found anymore. I pressed the button "Refresh field list" which actually made me see the field again, but it also added a myriad of fields that should not be there (fields that actually look like values). How can I fix this? Going back to the original ArcSight index. Thanks in advance!