Self hosted redash instance - No ElasticSearch queries work


I am self hosting the latest version of redash and have successfully setup mysql, mongo and ES data sources.
In ES datasource, however, I cannot get any queries working, even the simplest ones by following the documentation.

Note: I am running ES 6.3, Redis 6.0.0+b8537 - not sure if there are compatibility problems with ES 6.x (I couldn’t find much documentation about it on redash) - or any workarounds if this is the problem.

Here’s a simple query with the accompanying error:

The same query but this time when I add a “limit” attribute as in the documentation: