I can't convert cif to fasta file

[minhphi1712]

python3 cif2fasta.py -i /home/sandhyap/dataset -o pdb100.fas -c 3 -p pdb_filter.dat
Found: 5 files.
multiprocessing.pool.RemoteTraceback:
"""
Traceback (most recent call last):
File "/usr/lib64/python3.6/multiprocessing/pool.py", line 119, in worker
result = (True, func(*args, **kwds))
File "/usr/lib64/python3.6/multiprocessing/pool.py", line 44, in mapstar
return list(map(*args))
File "cif2fasta.py", line 711, in wrapper_function
fasta_entry = create_fasta_entry2(cif2fasta)
File "cif2fasta.py", line 613, in create_fasta_entry2
protein_description = cif2fasta.protein_description()
File "cif2fasta.py", line 265, in protein_description
protein_description = struct.getValue('pdbx_descriptor')
File "/home/sandhyap/.local/lib/python3.6/site-packages/pdbx/reader/PdbxContainers.py", line 464, in getValue
return self._rowList[rowI][self._attributeNameList.index(attribute)]
ValueError: 'pdbx_descriptor' is not in list
"""

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
File "cif2fasta.py", line 791, in
main()
File "cif2fasta.py", line 784, in main
fastas = pool.map(wrapper_function, paths)
File "/usr/lib64/python3.6/multiprocessing/pool.py", line 266, in map
return self._map_async(func, iterable, mapstar, chunksize).get()
File "/usr/lib64/python3.6/multiprocessing/pool.py", line 644, in get
raise self._value
ValueError: 'pdbx_descriptor' is not in list