Question: I am trying to connect elasticsearch as output connector from apache ManifoldCF.Using elasticsearch 7.1.X version which is not working. 

Can you suggest will maniFoldCF work with latest elasticsearch version ?

Tried configuring the repository and output plugin with elasticsearch. Executed a job but nothing turned up in elasticsearch.

Data should be crawled from repo to elasticsearch index. But its not happening with latest elasticsearch version.

Answer: 
The latest release of ManifoldCF was tested successfully for version 7.x. See this ticket:

<https://issues.apache.org/jira/browse/CONNECTORS-1639>
Looking at the output connector interoperability notes for version 2.15 (the latest as of this writing) the Elasticsearch connector was tested against 1.x instances `Tested with ElasticSearch 1.0, 1.1, 1.2, 1.3` [Included Connectors](https://manifoldcf.apache.org/release/release-2.15/en_US/included-connectors.html). Knowing of breaking changes in both ES 6.x and 7.x releases I would guess the connector will need some modifications to work with the latest 6, 7, and maybe even 5.x versions of Elasticsearch. Should be a relatively simple task to clone the default connector and make the changes to add support though.