TLDR: The presence of the string `__SPEAKEASY_UNSET__` in a field expected to contain a date is causing errors in the Python SDK. @Andre Rabold said: > Good morning! it seems since last week I’m running into a new problem with the Python SDK when dealing with optional nullable (?) date/time fields. The unmarshalling of the data fails with the call stack below. The offending data/time fields are not set but completely excluded from the response. > > ``` > File "/opt/anaconda3/lib/python3.11/site-packages/autounify/utils/utils.py", line 825, in unmarshal_json > out = unmarshal.from_dict({"res": json_dict}, infer_missing=infer_missing) > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > File "/opt/anaconda3/lib/python3.11/site-packages/dataclasses_json/api.py", line 70, in from_dict > return _decode_dataclass(cls, kvs, infer_missing) > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > File "/opt/anaconda3/lib/python3.11/site-packages/dataclasses_json/core.py", line 233, in _decode_dataclass > init_kwargs[field.name] = _decode_generic(field_type, > ^^^^^^^^^^^^^^^^^^^^^^^^^^^ > File "/opt/anaconda3/lib/python3.11/site-packages/dataclasses_json/core.py", line 329, in _decode_generic > res = _decode_type(type_arg, value, infer_missing) > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > File "/opt/anaconda3/lib/python3.11/site-packages/dataclasses_json/core.py", line 247, in _decode_type > return _decode_generic(type_, value, infer_missing) > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > File "/opt/anaconda3/lib/python3.11/site-packages/dataclass... > ```