Elasticsearch Cluster authentication failed


I use couchbase 4.0.0-4051, elasticsearch 2.3.5 and transport plugin

After having add username and password in elasticsearch conf file elasticsearch don’t start.

echo “couchbase.password: aaaaaaaa” >> elasticsearch.yml
echo “couchbase.username: Administrator” >> elasticsearch.yml
echo “couchbase.maxConcurrentRequests: 1024” >> elasticsearch.yml

Without the conf I can connect to 9091 port and the connexion works when I just put Administrator as login and leave blank for password.

Is there a bug ?

Kind regards