Downloading js player vfl49f_g4 ; ERROR: Signature extraction failed ; RegexNotFoundError('Unable to extract %s' % _name)

[Golutazem]

Using current git head version 2e11e51c041bd95dd1305af5b958abacc27f39f7
2019.05.20 and also 2019.05.11.

Attempting to retrieve information about or to download some videos results in the message
Downloading js player vfl49f_g4
and the error

ERROR: Signature extraction failed: Traceback (most recent call last):
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1342, in _decrypt_signature
    video_id, player_url, s
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1250, in _extract_signature_function
    res = self._parse_sig_js(code)
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1314, in _parse_sig_js
    jscode, 'Initial JS player signature function name', group='sig')
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/common.py", line 1004, in _search_regex
    raise RegexNotFoundError('Unable to extract %s' % _name)
youtube_dl.utils.RegexNotFoundError: Unable to extract Initial JS player signature function name;

One such video is
https://www.youtube.com/watch?v=OyBNmecVtdU

Here is a verbose log:

[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['-vF', 'https://www.youtube.com/watch?v=OyBNmecVtdU']
[debug] Encodings: locale UTF-8, fs utf-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2019.05.20
[debug] Python version 3.7.3 (CPython) - Linux-5.1.4
[debug] exe versions: ffmpeg 4.1.3, ffprobe 4.1.3, phantomjs 2.1.1, rtmpdump 2.4
[debug] Proxy map: {}
[youtube] OyBNmecVtdU: Downloading webpage
[youtube] OyBNmecVtdU: Downloading video info webpage
[youtube] {22} signature length 104, html5 player vfl49f_g4
[youtube] OyBNmecVtdU: Downloading player https://www.youtube.com/yts/jsbin/player_ias-vfl49f_g4/en_US/base.js
ERROR: Signature extraction failed: Traceback (most recent call last):
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 1342, in _decrypt_signature
    video_id, player_url, s
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 1250, in _extract_signature_function
    res = self._parse_sig_js(code)
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 1314, in _parse_sig_js
    jscode, 'Initial JS player signature function name', group='sig')
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/common.py", line 1005, 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 . Make sure you are using the latest version; type  youtube-dl -U  to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.
 (caused by RegexNotFoundError('Unable to extract Initial JS player signature function name; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; type  youtube-dl -U  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; type  youtube-dl -U  to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.
Traceback (most recent call last):
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 1342, in _decrypt_signature
    video_id, player_url, s
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 1250, in _extract_signature_function
    res = self._parse_sig_js(code)
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 1314, in _parse_sig_js
    jscode, 'Initial JS player signature function name', group='sig')
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/common.py", line 1005, 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 . Make sure you are using the latest version; type  youtube-dl -U  to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.
Traceback (most recent call last):
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 1342, in _decrypt_signature
    video_id, player_url, s
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 1250, in _extract_signature_function
    res = self._parse_sig_js(code)
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 1314, in _parse_sig_js
    jscode, 'Initial JS player signature function name', group='sig')
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/common.py", line 1005, 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 . Make sure you are using the latest version; type  youtube-dl -U  to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/bin/youtube-dl/youtube_dl/YoutubeDL.py", line 796, in extract_info
    ie_result = ie.extract(url)
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/common.py", line 530, in extract
    ie_result = self._real_extract(url)
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 1986, in _real_extract
    encrypted_sig, video_id, player_url, age_gate)
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 1352, in _decrypt_signature
    'Signature extraction failed: ' + tb, cause=e)
youtube_dl.utils.ExtractorError: Signature extraction failed: Traceback (most recent call last):
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 1342, in _decrypt_signature
    video_id, player_url, s
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 1250, in _extract_signature_function
    res = self._parse_sig_js(code)
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 1314, in _parse_sig_js
    jscode, 'Initial JS player signature function name', group='sig')
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/common.py", line 1005, in _search_regex
    raise RegexNotFoundError('Unable to extract %s' % _name)
youtube_dl.utils.RegexNotFoundError: Unable to extract Initial JS player signature function name;

[dstftw]

Using current git head version 2e11e51
2019.05.20 and also 2019.05.11.

Wrong.