[Core] Started seeing the error 'str' object has no attribute 'language'

While using Ray SGD distributed tensor flow, I started to see the below errors.

ERROR serialization.py:248 -- 'str' object has no attribute 'language'
    Traceback (most recent call last):
     File "/home/elevoai/elevo-0.0.1/elevo_venv/lib/python3.7/site-packages/ray/serialization.py", line 246, in deserialize_objects
     obj = self._deserialize_object(data, metadata, object_ref)
     File "/home/elevoai/elevo-0.0.1/elevo_venv/lib/python3.7/site-packages/ray/serialization.py", line 211, in _deserialize_object
return RayError.from_bytes(obj)
    File "/home/elevoai/elevo-0.0.1/elevo_venv/lib/python3.7/site-packages/ray/exceptions.py", line 29, in from_bytes
return pickle.loads(ray_exception.serialized_exception)
   File "/home/elevoai/elevo-0.0.1/elevo_venv/lib/python3.7/site-packages/ray/exceptions.py", line 39, in __init__
  AttributeError: 'str' object has no attribute 'language'

What is the root cause of this issue.

I have a couple questions to follow up;

  1. What’s the version of Ray are you using?
  2. Do you have a repro script to the issue? I’ve never seen the issue before.