ERROR: Signature extraction failed: Traceback (most recent call last):

[kikoshiro]

dominik@sirius ~/Downloads/musik $ youtube-dl --verbose https://www.youtube.com/watch?v=4oB2l9Fxf6c
[debug] System config: []
[debug] User config: []
[debug] Command-line args: [u'--verbose', u'https://www.youtube.com/watch?v=4oB2l9Fxf6c']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2016.02.22
[debug] Python version 2.7.12 - Linux-4.4.0-21-generic-x86_64-with-LinuxMint-18-sarah
[debug] exe versions: none
[debug] Proxy map: {}
[youtube] 4oB2l9Fxf6c: Downloading webpage
[youtube] 4oB2l9Fxf6c: Downloading video info webpage
[youtube] 4oB2l9Fxf6c: Extracting video information
[youtube] {22} signature length 41.40, html5 player en_US-vflxP8f0T
[youtube] 4oB2l9Fxf6c: Downloading player https://s.ytimg.com/yts/jsbin/player-en_US-vflxP8f0T/base.js
ERROR: Signature extraction failed: Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 905, in _decrypt_signature
video_id, player_url, s
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 820, in _extract_signature_function
res = self._parse_sig_js(code)
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 883, in _parse_sig_js
initial_function = jsi.extract_function(funcname)
File "/usr/lib/python2.7/dist-packages/youtube_dl/jsinterp.py", line 241, in extract_function
raise ExtractorError('Could not find JS function %r' % funcname)
ExtractorError: Could not find JS function u'xm'; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see https://yt-dl.org/update on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.
(caused by ExtractorError(u"Could not find JS function u'xm'; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see https://yt-dl.org/update on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.",)); please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see https://yt-dl.org/update on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.
Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 905, in _decrypt_signature
video_id, player_url, s
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 820, in _extract_signature_function
res = self._parse_sig_js(code)
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 883, in _parse_sig_js
initial_function = jsi.extract_function(funcname)
File "/usr/lib/python2.7/dist-packages/youtube_dl/jsinterp.py", line 241, in extract_function
raise ExtractorError('Could not find JS function %r' % funcname)
ExtractorError: Could not find JS function u'xm'; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see https://yt-dl.org/update on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.
Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/youtube_dl/YoutubeDL.py", line 666, in extract_info
ie_result = ie.extract(url)
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/common.py", line 316, in extract
return self._real_extract(url)
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 1407, in _real_extract
encrypted_sig, video_id, player_url, age_gate)
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 915, in _decrypt_signature
'Signature extraction failed: ' + tb, cause=e)
ExtractorError: Signature extraction failed: Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 905, in _decrypt_signature
video_id, player_url, s
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 820, in _extract_signature_function
res = self._parse_sig_js(code)
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 883, in _parse_sig_js
initial_function = jsi.extract_function(funcname)
File "/usr/lib/python2.7/dist-packages/youtube_dl/jsinterp.py", line 241, in extract_function
raise ExtractorError('Could not find JS function %r' % funcname)
ExtractorError: Could not find JS function u'xm'; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see https://yt-dl.org/update on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.
(caused by ExtractorError(u"Could not find JS function u'xm'; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see https://yt-dl.org/update on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.",)); please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see https://yt-dl.org/update on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.

dominik@sirius ~/Downloads/musik $

Hope This helps?

[dstftw]

You are using an outdated version of youtube-dl. Read this FAQ entry if you have troubles updating.