youtube-dl: Niconico download does not work anymore

Please follow the guide below

• You will be asked some questions and requested to provide some information, please read them carefully and answer honestly
• Put an x into all the boxes [ ] relevant to your issue (like that [x])
• Use Preview tab to see how your issue will actually look like

---

Make sure you are using the latest version: run youtube-dl --version and ensure your version is 2016.11.08.1. If it’s not read this FAQ entry and update. Issues with outdated version will be rejected.

• I’ve verified and I assure that I’m running youtube-dl 2016.11.08.1

Before submitting an issue make sure you have:

• At least skimmed through README and most notably FAQ and BUGS sections
• Searched the bugtracker for similar issues including closed ones

What is the purpose of your issue?

• Bug report (encountered problems with youtube-dl)
• Site support request (request for adding support for a new site)
• Feature request (request for a new functionality)
• Question
• Other

---

The following sections concretize particular purposed issues, you can erase any section (the contents between triple —) not applicable to your issue

---

If the purpose of this issue is a bug report, site support request or you are not completely sure provide the full verbose output as follows:

Add -v flag to your command line you run youtube-dl with, copy the whole output and insert it here. It should look similar to one below (replace it with your log inserted between triple ```):

# youtube-dl http://www.nicovideo.jp/watch/sm30023059 --verbose
[debug] System config: []
[debug] User config: []
[debug] Command-line args: [u'http://www.nicovideo.jp/watch/sm30023059', u'--verbose']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2016.11.08.1
[debug] Python version 2.7.9 - Linux-4.4.30-rm2+-x86_64-with-debian-8.6
[debug] exe versions: none
[debug] Proxy map: {}
[niconico] sm30023059: Downloading webpage
[niconico] sm30023059: Downloading video info page
[niconico] sm30023059: Downloading webpage
ERROR: Unable to extract thumbPlayKey; 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 694, in extract_info
    ie_result = ie.extract(url)
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/common.py", line 357, in extract
    return self._real_extract(url)
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/niconico.py", line 141, in _real_extract
    r'\'thumbPlayKey\'\s*:\s*\'(.*?)\'', ext_player_info, 'thumbPlayKey')
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/common.py", line 660, in _search_regex
    raise RegexNotFoundError('Unable to extract %s' % _name)
RegexNotFoundError: Unable to extract thumbPlayKey; 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.

---

Description of your issue, suggested solution and other information

Used to work until very recently, but now it doesn’t. I have looked through the source of the Niconico page and indeed it doesn’t contain a string like “thumbPlayKey”.