Automatic signature extraction failed

[aaruni96]

$ youtube-dl --verbose https://www.youtube.com/watch?v=HTzGMEfbnAw
[debug] System config: []
[debug] User config: []
[debug] Command-line args: ['--verbose', 'https://www.youtube.com/watch?v=HTzGMEfbnAw']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2014.07.21
[debug] Python version 2.7.3 - Linux-3.13.0-32-generic-x86_64-with-Ubuntu-12.04-precise
[debug] Proxy map: {}
[youtube] Setting language
[youtube] HTzGMEfbnAw: Downloading webpage
[youtube] HTzGMEfbnAw: Downloading video info webpage
[youtube] HTzGMEfbnAw: Extracting video information
[youtube] HTzGMEfbnAw: Encrypted signatures detected.
[youtube] encrypted signature length 84 (43.40), itag 43, html5 player en_US-vflArxUZc/html5player
ERROR: Automatic signature extraction failed: Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 469, in _decrypt_signature
video_id, player_url, len(s)
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 351, in _extract_signature_function
player_type = id_m.group('ext')
AttributeError: 'NoneType' object has no attribute 'group'
; please report this issue on https://yt-dl.org/bug . Be sure to call youtube-dl with the --verbose flag and include its complete output. Make sure you are using the latest version; type youtube-dl -U to update.
Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 469, in _decrypt_signature
video_id, player_url, len(s)
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 351, in _extract_signature_function
player_type = id_m.group('ext')
AttributeError: 'NoneType' object has no attribute 'group'
Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/youtube_dl/YoutubeDL.py", line 516, in extract_info
ie_result = ie.extract(url)
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/common.py", line 169, in extract
return self._real_extract(url)
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 845, in _real_extract
encrypted_sig, video_id, player_url, age_gate)
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 479, in _decrypt_signature
u'Automatic signature extraction failed: ' + tb, cause=e)
ExtractorError: Automatic signature extraction failed: Traceback (most recent call last):
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 469, in _decrypt_signature
video_id, player_url, len(s)
File "/usr/lib/python2.7/dist-packages/youtube_dl/extractor/youtube.py", line 351, in _extract_signature_function
player_type = id_m.group('ext')
AttributeError: 'NoneType' object has no attribute 'group'
; please report this issue on https://yt-dl.org/bug . Be sure to call youtube-dl with the --verbose flag and include its complete output. Make sure you are using the latest version; type youtube-dl -U to update.

$ youtube-dl --version
2014.07.21

~$ python --version
Python 2.7.3

$ uname -a
Linux aaruni-HP-Pavilion-g6-Notebook-PC 3.13.0-32-generic #57~precise1-Ubuntu SMP Tue Jul 15 03:51:20 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

~$ youtube-dl -U
It looks like you installed youtube-dl with a package manager, pip, setup.py or a tarball. Please use that to update.

$ sudo apt-get install youtube-dl
Reading package lists... Done
Building dependency tree
Reading state information... Done
youtube-dl is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

[phihag]

You are using an outdated version of youtube-dl. YouTube changed their player on 2014-07-25, so you'll need at least youtube-dl version 2014.07.25 (or newer).

The version in your package manager's repositories is outdated though. You may need to contact the package maintainer, and request an update, and/or run sudo apt-get update.

Alternatively, uninstall the youtube-dl package and follow our manual installation instructions. From then on, you'll be able to update with sudo youtube-dl -U.