error when calling plot_stream()

[xyang2uchicago]

Hi, Stream team, I can follow almost all codes in the Jupyter Notebook but not the function plot_stream(). Can anyone help on debugging? I used my own adata object and called tthe function as:
st.plot_stream(adata,save_fig=True)

The error message is:
Traceback (most recent call last):
File "", line 1, in
File "/project/xyang2/software-packages/env/stream/lib/python3.7/site-packages/stream/core.py", line 3131, in plot_stream
log_scale=log_scale,factor_zoomin=factor_zoomin)
File "/project/xyang2/software-packages/env/stream/lib/python3.7/site-packages/stream/extra.py", line 933, in cal_stream_polygon_string
df_stream.loc[df_stream.index[id_cells],'edge'] = [x]
File "/project/xyang2/software-packages/env/stream/lib/python3.7/site-packages/pandas/core/indexing.py", line 723, in setitem
iloc._setitem_with_indexer(indexer, value, self.name)
File "/project/xyang2/software-packages/env/stream/lib/python3.7/site-packages/pandas/core/indexing.py", line 1730, in _setitem_with_indexer
self._setitem_with_indexer_split_path(indexer, value, name)
File "/project/xyang2/software-packages/env/stream/lib/python3.7/site-packages/pandas/core/indexing.py", line 1769, in _setitem_with_indexer_split_path
self._setitem_with_indexer_2d_value(indexer, value)
File "/project/xyang2/software-packages/env/stream/lib/python3.7/site-packages/pandas/core/indexing.py", line 1830, in _setitem_with_indexer_2d_value
"Must have equal len keys and value when setting with an ndarray"
ValueError: Must have equal len keys and value when setting with an ndarray