Hit Error while using this toolkits

[Ricardokevins]

Loading Named Entity Recognition Pipeline...
Loading Relation Extraction Pipeline...
Fact Score: 0.5714285714285714
Loading Question Generation Pipeline...
Loading Question Answering Pipeline...
Traceback (most recent call last):
File "testcase.py", line 5, in
print(factsumm(article, summary, verbose=False))
File "/usr/local/lib/python3.8/dist-packages/factsumm/init.py", line 366, in call
qags_score = self.extract_qas(
File "/usr/local/lib/python3.8/dist-packages/factsumm/init.py", line 263, in extract_qas
source_answers = self.qa(source, summary_qas)
File "/usr/local/lib/python3.8/dist-packages/factsumm/utils/level_sentence.py", line 100, in answer_question
pred = qa(
File "/usr/local/lib/python3.8/dist-packages/transformers/pipelines/question_answering.py", line 248, in call
return super().call(examples[0], **kwargs)
File "/usr/local/lib/python3.8/dist-packages/transformers/pipelines/base.py", line 915, in call
return self.run_single(inputs, preprocess_params, forward_params, postprocess_params)
File "/usr/local/lib/python3.8/dist-packages/transformers/pipelines/base.py", line 923, in run_single
outputs = self.postprocess(model_outputs, **postprocess_params)
File "/usr/local/lib/python3.8/dist-packages/transformers/pipelines/question_answering.py", line 409, in postprocess
min_null_score = min(min_null_score, (start_[0] * end_[0]).item())
ValueError: can only convert an array of size 1 to a Python scalar

while using provided example in README, I meet the Error above
( I use pip install to install this packet and create the python file, copy the example code and run )
pip uninstall and pip reinstall doesn`t help QAQ
any suggestion are greatly appreciated!