HTTPError: HTTP Error 404: Not Found

[vidhan13j07]

 $ youtube-dl https://www.youtube.com//watch?v=naKhF6G36rM -v
[debug] System config: []
[debug] User config: []
[debug] Command-line args: [u'https://www.youtube.com//watch?v=naKhF6G36rM', u'-v']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2015.10.09
[debug] Python version 2.7.10 - Linux-4.1.8-200.fc22.x86_64-x86_64-with-fedora-22-Twenty_Two
[debug] exe versions: none
[debug] Proxy map: {}
[generic] watch?v=naKhF6G36rM: Requesting header
WARNING: Falling back on generic information extractor.
[generic] watch?v=naKhF6G36rM: Downloading webpage
[generic] watch?v=naKhF6G36rM: Extracting information
[debug] Invoking downloader on u'https://www.youtube.com//\\/\\/www.youtube.com\\/annotations_invideo?cap_hist=1\\u0026video_id=naKhF6G36rM'
ERROR: unable to download video data: HTTP Error 404: Not Found
Traceback (most recent call last):
File "/usr/local/bin/youtube-dl/youtube_dl/YoutubeDL.py", line 1597, in process_info
success = dl(filename, info_dict)
File "/usr/local/bin/youtube-dl/youtube_dl/YoutubeDL.py", line 1539, in dl
return fd.download(name, info)
File "/usr/local/bin/youtube-dl/youtube_dl/downloader/common.py", line 342, in download
return self.real_download(filename, info_dict)
File "/usr/local/bin/youtube-dl/youtube_dl/downloader/http.py", line 60, in real_download
data = self.ydl.urlopen(request)
File "/usr/local/bin/youtube-dl/youtube_dl/YoutubeDL.py", line 1872, in urlopen
return self._opener.open(req, timeout=self._socket_timeout)
File "/usr/lib64/python2.7/urllib2.py", line 437, in open
response = meth(req, response)
File "/usr/lib64/python2.7/urllib2.py", line 550, in http_response
'http', request, response, code, msg, hdrs)
File "/usr/lib64/python2.7/urllib2.py", line 475, in error
return self._call_chain(_args)
File "/usr/lib64/python2.7/urllib2.py", line 409, in _call_chain
result = func(_args)
File "/usr/lib64/python2.7/urllib2.py", line 558, in http_error_default
raise HTTPError(req.get_full_url(), code, msg, hdrs, fp)
HTTPError: HTTP Error 404: Not Found

[yan12125]

There's an extra slash '/'. The following command works:

youtube-dl "https://www.youtube.com/watch?v=naKhF6G36rM" -v