HTTP Error 404

[n3h3m]

• [ x ] I'm reporting a broken site support issue
• [ x ] I've verified that I'm running youtube-dl version 2020.09.06
• [ x ] I've checked that all provided URLs are alive and playable in a browser
• [ x ] I've checked that all URLs and arguments with special characters are properly quoted or escaped
• [ x ] I've searched the bugtracker for similar bug reports including closed ones
• [ x ] I've read bugs section in FAQ

  02:20  ~  ytdl  21_studios  youtube-dl "https://www.youtube.com/21/videos" -v
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: [u'https://www.youtube.com/21/videos', u'-v']
[debug] Encodings: locale UTF-8, fs utf-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2020.09.06
[debug] Python version 2.7.16 (CPython) - Darwin-19.6.0-x86_64-i386-64bit
[debug] exe versions: ffmpeg 4.3.1, ffprobe 4.3.1, rtmpdump 2.4
[debug] Proxy map: {}
[youtube:user] 21: Downloading channel page
WARNING: Unable to download webpage: HTTP Error 404: Not Found
[youtube:user] 21: Downloading page #1
ERROR: Unable to download webpage: HTTP Error 404: Not Found (caused by HTTPError()); please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; type  youtube-dl -U  to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/common.py", line 627, in _request_webpage
    return self._downloader.urlopen(url_or_request)
  File "/usr/local/bin/youtube-dl/youtube_dl/YoutubeDL.py", line 2238, in urlopen
    return self._opener.open(req, timeout=self._socket_timeout)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 435, in open
    response = meth(req, response)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 548, in http_response
    'http', request, response, code, msg, hdrs)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 467, in error
    result = self._call_chain(*args)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 407, in _call_chain
    result = func(*args)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 654, in http_error_302
    return self.parent.open(new, timeout=req.timeout)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 435, in open
    response = meth(req, response)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 548, in http_response
    'http', request, response, code, msg, hdrs)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 473, in error
    return self._call_chain(*args)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 407, in _call_chain
    result = func(*args)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 556, in http_error_default
    raise HTTPError(req.get_full_url(), code, msg, hdrs, fp)

 02:21  ~  ytdl  21_studios 

[blackjack4494]

There is a workaround. If you watch any video of that channel you can click on the channel again. That will give you https://www.youtube.com/channel/UCuErSr7xeR763BzTJL7yJ7A you could then append /videos to it but that is not needed as the the link without /videos will also download all videos.

[llacb47]

Duplicate of #26316

[n3h3m]

Followed the workaround. Thanks @blackjack4494