ERROR: Signature extraction failed - ValueError: No JSON object could be decoded

[kradan]

$ sudo youtube-dl -U
youtube-dl is up-to-date (2014.08.10)

$ youtube-dl https://www.youtube.com/watch?v=zSAJ0l4OBHM -c --verbose
[debug] System config: []
[debug] User config: []
[debug] Command-line args: ['https://www.youtube.com/watch?v=zSAJ0l4OBHM', '-c', '--verbose']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2014.08.10
[debug] Python version 2.7.3 - Linux-3.2.0-4-amd64-x86_64-with-debian-7.6
[debug] Proxy map: {}
[youtube] Setting language
[youtube] zSAJ0l4OBHM: Downloading webpage
[youtube] zSAJ0l4OBHM: Downloading video info webpage
[youtube] zSAJ0l4OBHM: Extracting video information
[youtube] zSAJ0l4OBHM: Encrypted signatures detected.
[youtube] {43} signature length 41.43, html5 player en_US-vfl4b4S6W
ERROR: Signature extraction failed: Traceback (most recent call last):
File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 479, in _decrypt_signature
video_id, player_url, s
File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 373, in _extract_signature_function
cache_spec = json.load(cachef)
File "/usr/lib/python2.7/json/init.py", line 278, in load
*_kw)
File "/usr/lib/python2.7/json/init.py", line 326, in loads
return _default_decoder.decode(s)
File "/usr/lib/python2.7/json/decoder.py", line 365, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/usr/lib/python2.7/json/decoder.py", line 383, in raw_decode
raise ValueError("No JSON object could be decoded")
ValueError: No JSON object could be decoded
; 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 u
sing the latest version; type youtube-dl -U to update.
Traceback (most recent call last):
File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 479, in _decrypt_signature
video_id, player_url, s
File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 373, in _extract_signature_function
cache_spec = json.load(cachef)
File "/usr/lib/python2.7/json/init.py", line 278, in load
*_kw)
File "/usr/lib/python2.7/json/init.py", line 326, in loads
return _default_decoder.decode(s)
File "/usr/lib/python2.7/json/decoder.py", line 365, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/usr/lib/python2.7/json/decoder.py", line 383, in raw_decode
raise ValueError("No JSON object could be decoded")
ValueError: No JSON object could be decoded
Traceback (most recent call last):
File "/usr/local/bin/youtube-dl/youtube_dl/YoutubeDL.py", line 516, in extract_info
ie_result = ie.extract(url)
File "/usr/local/bin/youtube-dl/youtube_dl/extractor/common.py", line 170, in extract
return self._real_extract(url)
File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 860, in _real_extract
encrypted_sig, video_id, player_url, age_gate)
File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 489, in _decrypt_signature
ExtractorError: Signature extraction failed: Traceback (most recent call last):
File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 479, in _decrypt_signature
video_id, player_url, s
File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 373, in _extract_signature_function
cache_spec = json.load(cachef)
File "/usr/lib/python2.7/json/init.py", line 278, in load
**kw)
File "/usr/lib/python2.7/json/init.py", line 326, in loads
return _default_decoder.decode(s)
File "/usr/lib/python2.7/json/decoder.py", line 365, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
File "/usr/lib/python2.7/json/decoder.py", line 383, in raw_decode
raise ValueError("No JSON object could be decoded")
ValueError: No JSON object could be decoded
; 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.

[jaimeMF]

Could you post the contents of the ~/.cache/youtube-dl/youtube-sigfuncs/js_vfl4b4S6W_41.43.json file?

[kradan]

Unfortunately the file is empty.

[phihag]

@kradan Thank you. While we try to fix that, can you verify that running youtube-dl --rm-cache-dir once fixes this problem for you?

Checklist for us:

• Make cache writes atomic
• Fall back silently if cached version fails

[kradan]

Thanks! It works well with 2014.08.21.2 even without wiping the cache.