Exception in worker: "Failure processing workflow task"

Thanks for the clarifications Maxim. I will try to reset the entire docker image and start again since I am not sure how to get out of the mess at this point.
A final question: is there a Java API to perform the things that you do with tctl? For example, get all workflows currently ‘running’ and terminate each one in a loop?

Elastic search: I am seeing this: How to set up ElasticSearch? but it seems too much at this point just to get some dev tests running.

Costas