fbchat-archive-parser: Error when parsing messages

Traceback (most recent call last):                                               
  File "/Users/miroslav/anaconda3/bin/fbcap", line 11, in <module>
    sys.exit(fbcap())
  File "/Users/miroslav/anaconda3/lib/python3.6/site-packages/click/core.py", line 722, in __call__
    return self.main(*args, **kwargs)
  File "/Users/miroslav/anaconda3/lib/python3.6/site-packages/click/core.py", line 697, in main
    rv = self.invoke(ctx)
  File "/Users/miroslav/anaconda3/lib/python3.6/site-packages/click/core.py", line 895, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/Users/miroslav/anaconda3/lib/python3.6/site-packages/click/core.py", line 535, in invoke
    return callback(*args, **kwargs)
  File "/Users/miroslav/anaconda3/lib/python3.6/site-packages/fbchat_archive_parser/main.py", line 127, in fbcap
    write(fmt, fbch, directory or sys.stdout)
  File "/Users/miroslav/anaconda3/lib/python3.6/site-packages/fbchat_archive_parser/writers/__init__.py", line 44, in write
    selected_writer().write(data, stream_or_dir)
  File "/Users/miroslav/anaconda3/lib/python3.6/site-packages/fbchat_archive_parser/writers/writer.py", line 17, in write
    return self.write_history(data, stream)
  File "/Users/miroslav/anaconda3/lib/python3.6/site-packages/fbchat_archive_parser/writers/text.py", 
line 19, in write_history
    ('-' * len(history.user)) + "-\n"
TypeError: object of type 'NoneType' has no len()

Happens every time regardless. Does anyone have any idea what’s wrong?