i have trouble running dask on prefect, https://github.com/PrefectHQ/prefect/issues/3226 can anyone helps? i did try similar example using older version of prefect and it was working

Unexpected error: AttributeError("'NoneType' object has no attribute 'is_finished'")
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/prefect/engine/runner.py", line 48, in inner
    new_state = method(self, state, *args, **kwargs)
  File "/usr/local/lib/python3.7/site-packages/prefect/engine/task_runner.py", line 359, in check_upstream_finished
    if not all(s.is_finished() for s in all_states):
  File "/usr/local/lib/python3.7/site-packages/prefect/engine/task_runner.py", line 359, in <genexpr>
    if not all(s.is_finished() for s in all_states):
AttributeError: 'NoneType' object has no attribute 'is_finished'

any comment?

Hi @comet - hope all is well I am facing a very similar issue - I am getting the same traceback error ... did you manage to figure this out ?