org.elasticsearch.bootstrap.StartupException: java.lang.IllegalStateException: index and alias names need to be unique, but the following duplicates were found [.watches (alias of [.watches-6/WIUCyhnGQPqZxIZ7Advo6Q])]
I get errors like the above when I upgrae the kibana and watcher indexes coming from 5.6.6 going to 6.3.1. I can delete the folder WIUCyhnGQPqZxIZ7Advo6Q in the data directory and get the node to boot once but then it replicats from the other nodes and then next node to get cycled has the same issue.
I resolved it on Kibana by sending a curl statement to delete the kibana index and then set everything up again from scratch. this seems counter to how an upgrade helper is supposed to work though so if someone can give me some assistance please.