مشكلة عند استخدام مكتبة pafy

أهلا ومرحبا.

حدثت هذه المشكلة منذ أسبوع أو نحو ذلك. عندما أحاول بدء برنامجي ، وهو برنامج لمشاهدة وتنزيل مقاطع فيديو YouTube ، أرى هذا الخطأ:

Exception in thread Thread-4:
Traceback (most recent call last):
  File "C:\Users\ibraheem\AppData\Local\Programs\Python\Python38\lib\threading.py", line 932, in _bootstrap_inner
    self.run()
  File "C:\Users\ibraheem\AppData\Local\Programs\Python\Python38\lib\threading.py", line 870, in run
    self._target(*self._args, **self._kwargs)
  File "C:\Users\ibraheem\Downloads\YoutubeDownloader\source\gui\activity_dialog.py", line 34, in run
    raise e
  File "C:\Users\ibraheem\Downloads\YoutubeDownloader\source\gui\activity_dialog.py", line 30, in run
    self.res = self.function(*self.args, **self.kwargs)
  File "C:\Users\ibraheem\Downloads\YoutubeDownloader\source\utiles.py", line 27, in get_video_stream
    for stream in media.streams:
  File "C:\Users\ibraheem\Downloads\YoutubeDownloader\source\pafy\backend_shared.py", line 160, in streams
    self._process_streams()
  File "C:\Users\ibraheem\Downloads\YoutubeDownloader\source\pafy\backend_youtube_dl.py", line 83, in _process_streams
    allstreams = [YtdlStream(z, self) for z in self._ydl_info['formats']]
Traceback (most recent call last):
  File "C:\Users\ibraheem\Downloads\YoutubeDownloader\source\pafy\backend_youtube_dl.py", line 83, in <listcomp>
  File "C:\Users\ibraheem\Downloads\YoutubeDownloader\source\youtube_browser\browser.py", line 182, in <lambda>
    allstreams = [YtdlStream(z, self) for z in self._ydl_info['formats']]
  File "C:\Users\ibraheem\Downloads\YoutubeDownloader\source\pafy\backend_youtube_dl.py", line 107, in __init__
    self.searchResults.Bind(wx.EVT_MENU, lambda event: self.playVideo(), id=self.videoPlayItemId)
    self._rawbitrate = info.get('abr', 0) * 1024
  File "C:\Users\ibraheem\Downloads\YoutubeDownloader\source\youtube_browser\browser.py", line 134, in playVideo
TypeError: unsupported operand type(s) for *: 'NoneType' and 'int'
    stream = LoadingDialog(self, _("starting..."), get_video_stream, url).res
AttributeError: 'LoadingDialog' object has no attribute 'res'