[YouTube] Signature extraction failed

[kernelpanic1]

youtube-dl -v -F https://youtu.be/YQHsXMglC9A

[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: [u'-v', u'-F', u'https://youtu.be/YQHsXMglC9A']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2019.06.08
[debug] Python version 2.7.12 (CPython) - Linux-4.4.0-150-generic-x86_64-with-Ubuntu-16.04-xenial
[debug] exe versions: ffmpeg 4.1.3-0york1, ffprobe 4.1.3-0york1
[debug] Proxy map: {}
[youtube] YQHsXMglC9A: Downloading webpage
[youtube] YQHsXMglC9A: Downloading video info webpage
[youtube] {18} signature length 104, html5 player vfl49f_g4
[youtube] YQHsXMglC9A: 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)
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(u'Unable to extract \x1b[0;34mInitial JS player signature function name\x1b[0m; 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)
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/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)
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)
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(u'Unable to extract \x1b[0;34mInitial JS player signature function name\x1b[0m; 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.

is this a bug? or how can i fix it