I tried switching from the

LocalExecutor

which was working fine, to the

DaskExecutor

example from this page in the docs: https://docs.prefect.io/guide/tutorials/dask-cluster.html after making sure the scheduler and workers are running, when I try the flow, I get this error before it exits:

[2019-07-31 18:29:25,853] INFO - prefect.FlowRunner | Starting flow run.
distributed.protocol.pickle - INFO - Failed to serialize <bound method FlowRunner.run_task of <FlowRunner: open_states_to_elasticsearch>>. Exception: can't pickle _thread.lock objects
[2019-07-31 18:29:25,901] INFO - prefect.FlowRunner | Unexpected error: TypeError("can't pickle _thread.lock objects")
[2019-07-31 18:29:25,902] ERROR - prefect.Flow | Unexpected error occured in FlowRunner: TypeError("can't pickle _thread.lock objects")