gridfs.errors.CorruptGridFile: no chunk #0 about gridfsmigrate HOT 3 OPEN

2423. Dumping iqL6yZ5ZP3F3yK4ME Untersuchen_von_Silizium_Photomultipliern__SiPM__zur_Verwendung__in_der_Intensit_tsinterferometrie.pdf
2424. Dumping Bi85dHH23Kbao6WiR Tuerschilde.pdf
2425. Dumping ioWaWWpA5ZhdXpNgD lecture_literature.pdf
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/dist-packages/gridfs/grid_file.py", line 794, in next
    chunk = self._next_with_retry()
  File "/usr/local/lib/python3.7/dist-packages/gridfs/grid_file.py", line 786, in _next_with_retry
    return self._cursor.next()
  File "/usr/local/lib/python3.7/dist-packages/pymongo/cursor.py", line 1251, in next
    raise StopIteration
StopIteration

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "./migrate.py", line 244, in <module>
    obj.dumpfiles("rocketchat_uploads", store)
  File "./migrate.py", line 115, in dumpfiles
    data = res.read()
  File "/usr/local/lib/python3.7/dist-packages/gridfs/grid_file.py", line 606, in read
    return self._read_size_or_line(size=size)
  File "/usr/local/lib/python3.7/dist-packages/gridfs/grid_file.py", line 563, in _read_size_or_line
    buf = self.readchunk()
  File "/usr/local/lib/python3.7/dist-packages/gridfs/grid_file.py", line 529, in readchunk
    chunk = self.__chunk_iter.next()
  File "/usr/local/lib/python3.7/dist-packages/gridfs/grid_file.py", line 798, in next
    raise CorruptGridFile("no chunk #%d" % self._next_chunk)
gridfs.errors.CorruptGridFile: no chunk #0
I have no name!@b6ea9e515433:/bitnami/mongodb/upload_dump$