JS Player doesn't download error

[saruftw]

youtube-dl https://www.youtube.com/watch?v=I_izvAbhExY
[youtube] Setting language
[youtube] Confirming age
[youtube] I_izvAbhExY: Downloading webpage
[youtube] I_izvAbhExY: Downloading video info webpage
[youtube] I_izvAbhExY: Extracting video information
[youtube] I_izvAbhExY: Encrypted signatures detected.
[youtube] I_izvAbhExY: Downloading js player vflM7pYrM
ERROR: Signature extraction failed: Traceback (most recent call last):
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 532, in _decrypt_signature
    video_id, player_url, s
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 446, in _extract_signature_function
    res = self._parse_sig_js(code)
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 507, in _parse_sig_js
    'Initial JS player signature function name')
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/common.py", line 418, in _search_regex
    raise RegexNotFoundError('Unable to extract %s' % _name)
RegexNotFoundError: Unable to extract Initial JS player signature function name; 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.
 (caused by RegexNotFoundError(u'Unable to extract \x1b[0;34mInitial JS player signature function name\x1b[0m; 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.',)); 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

[phihag]

Sorry, we need more information to diagnose this problem. As mentioned in the error message:

Be sure to call youtube-dl with the --verbose flag and include its complete output.
Make sure you are using the latest version; type sudo youtube-dl -U to update.

[WishCow]

Same problem.

[debug] System config: []
[debug] User config: []
[debug] Command-line args: ['-x', '--audio-format', 'mp3', '--verbose', 'http://www.youtube.com/watch?v=mk48xRzuNvA']
[debug] Encodings: locale UTF-8, fs utf-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2014.10.05.2
[debug] Python version 3.4.2 - Linux-3.17.2-1-ARCH-x86_64-with-arch
[debug] Proxy map: {}
[youtube] Setting language
[youtube] Confirming age
[youtube] mk48xRzuNvA: Downloading webpage
[youtube] mk48xRzuNvA: Downloading video info webpage
[youtube] mk48xRzuNvA: Extracting video information
[youtube] mk48xRzuNvA: Encrypted signatures detected.
[youtube] {22} signature length 40.42, html5 player en_US-vflM7pYrM
[youtube] mk48xRzuNvA: Downloading js player vflM7pYrM
ERROR: Signature extraction failed: Traceback (most recent call last):
  File "/usr/lib/python3.4/site-packages/youtube_dl/extractor/youtube.py", line 532, in _decrypt_signature
    video_id, player_url, s
  File "/usr/lib/python3.4/site-packages/youtube_dl/extractor/youtube.py", line 446, in _extract_signature_function
    res = self._parse_sig_js(code)
  File "/usr/lib/python3.4/site-packages/youtube_dl/extractor/youtube.py", line 507, in _parse_sig_js
    'Initial JS player signature function name')
  File "/usr/lib/python3.4/site-packages/youtube_dl/extractor/common.py", line 418, in _search_regex
    raise RegexNotFoundError('Unable to extract %s' % _name)
youtube_dl.utils.RegexNotFoundError: Unable to extract Initial JS player signature function name; 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.
 (caused by RegexNotFoundError('Unable to extract Initial JS player signature function name; 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.',)); 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/python3.4/site-packages/youtube_dl/extractor/youtube.py", line 532, in _decrypt_signature
    video_id, player_url, s
  File "/usr/lib/python3.4/site-packages/youtube_dl/extractor/youtube.py", line 446, in _extract_signature_function
    res = self._parse_sig_js(code)
  File "/usr/lib/python3.4/site-packages/youtube_dl/extractor/youtube.py", line 507, in _parse_sig_js
    'Initial JS player signature function name')
  File "/usr/lib/python3.4/site-packages/youtube_dl/extractor/common.py", line 418, in _search_regex
    raise RegexNotFoundError('Unable to extract %s' % _name)
youtube_dl.utils.RegexNotFoundError: Unable to extract Initial JS player signature function name; 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/python3.4/site-packages/youtube_dl/extractor/youtube.py", line 532, in _decrypt_signature
    video_id, player_url, s
  File "/usr/lib/python3.4/site-packages/youtube_dl/extractor/youtube.py", line 446, in _extract_signature_function
    res = self._parse_sig_js(code)
  File "/usr/lib/python3.4/site-packages/youtube_dl/extractor/youtube.py", line 507, in _parse_sig_js
    'Initial JS player signature function name')
  File "/usr/lib/python3.4/site-packages/youtube_dl/extractor/common.py", line 418, in _search_regex
    raise RegexNotFoundError('Unable to extract %s' % _name)
youtube_dl.utils.RegexNotFoundError: Unable to extract Initial JS player signature function name; 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.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.4/site-packages/youtube_dl/YoutubeDL.py", line 524, in extract_info
    ie_result = ie.extract(url)
  File "/usr/lib/python3.4/site-packages/youtube_dl/extractor/common.py", line 193, in extract
    return self._real_extract(url)
  File "/usr/lib/python3.4/site-packages/youtube_dl/extractor/youtube.py", line 927, in _real_extract
    encrypted_sig, video_id, player_url, age_gate)
  File "/usr/lib/python3.4/site-packages/youtube_dl/extractor/youtube.py", line 542, in _decrypt_signature
    'Signature extraction failed: ' + tb, cause=e)
youtube_dl.utils.ExtractorError: Signature extraction failed: Traceback (most recent call last):
  File "/usr/lib/python3.4/site-packages/youtube_dl/extractor/youtube.py", line 532, in _decrypt_signature
    video_id, player_url, s
  File "/usr/lib/python3.4/site-packages/youtube_dl/extractor/youtube.py", line 446, in _extract_signature_function
    res = self._parse_sig_js(code)
  File "/usr/lib/python3.4/site-packages/youtube_dl/extractor/youtube.py", line 507, in _parse_sig_js
    'Initial JS player signature function name')
  File "/usr/lib/python3.4/site-packages/youtube_dl/extractor/common.py", line 418, in _search_regex
    raise RegexNotFoundError('Unable to extract %s' % _name)
youtube_dl.utils.RegexNotFoundError: Unable to extract Initial JS player signature function name; 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.
 (caused by RegexNotFoundError('Unable to extract Initial JS player signature function name; 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.',)); 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.

[phihag]

@WishCow You are using an outdated version of youtube-dl (the YouTube player changed on November 13th, 2014, so you'll need youtube-dl 2014.11.13 or newer). See our FAQ on how to update.

We tried notifying you in advance by adding

Make sure you are using the latest version; type youtube-dl -U to update.

to the error output. Was there something in there that you did not understand? Can you suggest how we could rephrase the output to advise users to update before reporting bugs? Don't get me wrong, I appreciate every bug report we get, but it would be a lot simpler both for users and developers when users would update to the current version before reporting bugs.

[saruftw]

Update fixed it.

[WishCow]

I did try youtube-dl -U, which told me I should use the package manager to update it, which said there are no updates, so I looked at the package's page to see if it's marked as outdated, which told me that it's not outdated.

I came here to see if the error is mentioned in the issues list, and I saw that it's only missing the detailed error message, so I might as well add it.

I did not check the official download page, about what the latest version is, my bad.

As for improving the error message:
It could say "You have version X installed, but there is an updated version Y, please use that".

[phihag]

Ok thank you for the suggestion. The problem with naming the current version is that it requires a working Internet connection, so it may lead to additional failures. We'll try to clarify that.