System issue

[Arielode]

Hi developers,
Thanks for the useful tool!
but when I try example data with default code "scAllele -b testdata/gm12878.chr21.bam -g testdata/hg38.chr21.fa -o ./test_",
I got an error message: "SystemError: returned a result with an error set"

Traceback (most recent call last):
File "/miniconda3/bin/scAllele", line 8, in
sys.exit(main())
File "/miniconda3/lib/python3.9/site-packages/scAllele/scAllele.py", line 396, in main
for rc_output in pool.imap_unordered(process_read_cluster_1, ARGs):
File "~/miniconda3/lib/python3.9/multiprocessing/pool.py", line 870, in next
raise value

Is this error related to the python package version or something else? have no idea....
Any advise would be helpful. Thanks.

Best regards,
Arial