Replication Error to ElasticSearch


I have an existing replication in Couchbase -> ElasticSearch.

It was working alright before but now I noticed that there are always errors displayed in the XDCR Errors and all are the same:
“Failed to connect to cluster reference remoteCluster/”

When I tried to add a new replication, this message was also shown and therefore I was not able to create it. I checked in elasticsearch_plugin head and I can query with results in there.

What else do I need to check to fix it? Our application now does not retrieve any results from elastic search though.