cannot download some YouTube video

[die-Deutsche-Orthopaedie]

when i try to download some videos like this:

youtube-dl -f bestaudio -o "%(title)s (%(id)s).m4a" "https://www.youtube.com/watch?v=dD40VXFkusw" --verbose

i got:

[debug] System config: [u'--prefer-free-formats']
[debug] User config: []
[debug] Command-line args: [u'-f', u'bestaudio', u'-o', u'%(title)s (%(id)s).m4a', u'https://www.youtube.com/watch?v=dD40VXFkusw', u'--verbose']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2015.11.13
[debug] Python version 2.7.5 - Linux-3.10.0-229.20.1.el7.x86_64-x86_64-with-centos-7.2.1511-Core
[debug] exe versions: ffmpeg 2.6.5, ffprobe 2.6.5
[debug] Proxy map: {}
[youtube] dD40VXFkusw: Downloading webpage
[youtube] dD40VXFkusw: Downloading video info webpage
[youtube] dD40VXFkusw: Extracting video information
[youtube] {22} signature length 44.41, html5 player en_US-vfl1SLb2X
[youtube] dD40VXFkusw: Downloading player https://s.ytimg.com/yts/jsbin/player-en_US-vfl1SLb2X/base.js
ERROR: Signature extraction failed: Traceback (most recent call last):
File "/usr/lib/python2.7/site-packages/youtube_dl/extractor/youtube.py", line 817, in _decrypt_signature
video_id, player_url, s
File "/usr/lib/python2.7/site-packages/youtube_dl/extractor/youtube.py", line 732, in _extract_signature_function
res = self._parse_sig_js(code)
File "/usr/lib/python2.7/site-packages/youtube_dl/extractor/youtube.py", line 795, in _parse_sig_js
initial_function = jsi.extract_function(funcname)
File "/usr/lib/python2.7/site-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'ir'; 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'ir'; 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/site-packages/youtube_dl/extractor/youtube.py", line 817, in _decrypt_signature
video_id, player_url, s
File "/usr/lib/python2.7/site-packages/youtube_dl/extractor/youtube.py", line 732, in _extract_signature_function
res = self._parse_sig_js(code)
File "/usr/lib/python2.7/site-packages/youtube_dl/extractor/youtube.py", line 795, in _parse_sig_js
initial_function = jsi.extract_function(funcname)
File "/usr/lib/python2.7/site-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'ir'; 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/site-packages/youtube_dl/YoutubeDL.py", line 661, in extract_info
ie_result = ie.extract(url)
File "/usr/lib/python2.7/site-packages/youtube_dl/extractor/common.py", line 290, in extract
return self._real_extract(url)
File "/usr/lib/python2.7/site-packages/youtube_dl/extractor/youtube.py", line 1356, in _real_extract
encrypted_sig, video_id, player_url, age_gate)
File "/usr/lib/python2.7/site-packages/youtube_dl/extractor/youtube.py", line 827, in _decrypt_signature
'Signature extraction failed: ' + tb, cause=e)
ExtractorError: Signature extraction failed: Traceback (most recent call last):
File "/usr/lib/python2.7/site-packages/youtube_dl/extractor/youtube.py", line 817, in _decrypt_signature
video_id, player_url, s
File "/usr/lib/python2.7/site-packages/youtube_dl/extractor/youtube.py", line 732, in _extract_signature_function
res = self._parse_sig_js(code)
File "/usr/lib/python2.7/site-packages/youtube_dl/extractor/youtube.py", line 795, in _parse_sig_js
initial_function = jsi.extract_function(funcname)
File "/usr/lib/python2.7/site-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'ir'; 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'ir'; 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.

so i don't know what's wrong with that video, and some others in search results of "Rusko - Everyday (Netsky Remix)"?

[yan12125]

[debug] youtube-dl version 2015.11.13

You're using an out-dated version. The latest version is 2016.01.15. Please update your copy. See this FAQ entry for more information.

[die-Deutsche-Orthopaedie]

nothin' wrong on 2016.01.15 release. thanks.