youtube-dl: [YouTube] Signature videos return 403 forbidden sporadically from multiple locations

Checklist

• I’m reporting a broken site support issue
• I’ve verified that I’m running youtube-dl version 2020.03.24
• I’ve checked that all provided URLs are alive and playable in a browser
• I’ve checked that all URLs and arguments with special characters are properly quoted or escaped
• I’ve searched the bugtracker for similar bug reports including closed ones
• I’ve read bugs section in FAQ

Verbose log

[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['--verbose', 'https://www.youtube.com/watch?v=Vs6sWjiE9Yo']
[debug] Encodings: locale UTF-8, fs utf-8, out utf-8, pref UTF-8
[debug] youtube-dl version 2020.03.24
[debug] Python version 3.8.0 (CPython) - macOS-10.15.4-x86_64-i386-64bit
[debug] exe versions: ffmpeg 4.2.2, ffprobe 4.2.2, rtmpdump 2.4
[debug] Proxy map: {}
[youtube] Vs6sWjiE9Yo: Downloading webpage
[youtube] {18} signature length 112, html5 player vflset
[youtube] {137} signature length 108, html5 player vflset
[youtube] {248} signature length 108, html5 player vflset
[youtube] {136} signature length 112, html5 player vflset
[youtube] {247} signature length 108, html5 player vflset
[youtube] {135} signature length 108, html5 player vflset
[youtube] {244} signature length 112, html5 player vflset
[youtube] {134} signature length 112, html5 player vflset
[youtube] {243} signature length 112, html5 player vflset
[youtube] {133} signature length 112, html5 player vflset
[youtube] {242} signature length 112, html5 player vflset
[youtube] {160} signature length 112, html5 player vflset
[youtube] {278} signature length 112, html5 player vflset
[youtube] {140} signature length 108, html5 player vflset
[youtube] {249} signature length 112, html5 player vflset
[youtube] {250} signature length 112, html5 player vflset
[youtube] {251} signature length 112, html5 player vflset
[debug] Default format spec: bestvideo+bestaudio/best
WARNING: Requested formats are incompatible for merge and will be merged into mkv.
[debug] Invoking downloader on 'https://r5---sn-5ualdn7r.googlevideo.com/videoplayback?expire=1586502501&ei=BMePXtzHOayYkATIxK7ADQ&ip=XXXXXXXXXXX&id=o-AAH0LVoUlAR7RQ1qGwQvTPRuyctCFU5JhzcD7iKPqh6K&itag=137&aitags=133%2C134%2C135%2C136%2C137%2C160%2C242%2C243%2C244%2C247%2C248%2C278&source=youtube&requiressl=yes&mh=Ks&mm=31%2C29&mn=sn-5ualdn7r%2Csn-5uaeznkl&ms=au%2Crdu&mv=m&mvi=4&pl=21&gcr=us&initcwndbps=891250&vprv=1&mime=video%2Fmp4&gir=yes&clen=13539610&dur=156.840&lmt=1569617025630284&mt=1586480860&fvip=5&keepalive=yes&beids=9466585&c=WEB&txp=8311222&sparams=expire%2Cei%2Cip%2Cid%2Caitags%2Csource%2Crequiressl%2Cgcr%2Cvprv%2Cmime%2Cgir%2Cclen%2Cdur%2Clmt&lsparams=mh%2Cmm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps&lsig=ALrAebAwRQIhAIEA4w3kS1womr49qUNdh7X_1lgpaqrXG1UHaqBREOw0AiAzqzIdcowPg-N4dnZH_fJ8cZas3R8Lf2PHlH6Nj5TDdQ%3D%3D&sig=3E777ERE4ptxjqiscEOQz9-1bIMNfwXTJYu9tIti7Tr23jV0BICMYEARq7df8huONwV0uC4INSsqOY_Yn_o0Lkg2lb5rhNgIARwsLlPpJk&ratebypass=yes'
ERROR: unable to download video data: HTTP Error 403: Forbidden
Traceback (most recent call last):
  File "/venv/lib/python3.8/site-packages/youtube_dl/YoutubeDL.py", line 1921, in process_info
    partial_success = dl(fname, new_info)
  File "/venv/lib/python3.8/site-packages/youtube_dl/YoutubeDL.py", line 1866, in dl
    return fd.download(name, info)
  File "/venv/lib/python3.8/site-packages/youtube_dl/downloader/common.py", line 366, in download
    return self.real_download(filename, info_dict)
  File "/venv/lib/python3.8/site-packages/youtube_dl/downloader/http.py", line 341, in real_download
    establish_connection()
  File "/venv/lib/python3.8/site-packages/youtube_dl/downloader/http.py", line 109, in establish_connection
    ctx.data = self.ydl.urlopen(request)
  File "/venv/lib/python3.8/site-packages/youtube_dl/YoutubeDL.py", line 2239, in urlopen
    return self._opener.open(req, timeout=self._socket_timeout)
  File "/.pyenv/versions/3.8.0/lib/python3.8/urllib/request.py", line 531, in open
    response = meth(req, response)
  File "/.pyenv/versions/3.8.0/lib/python3.8/urllib/request.py", line 640, in http_response
    response = self.parent.error(
  File "/.pyenv/versions/3.8.0/lib/python3.8/urllib/request.py", line 569, in error
    return self._call_chain(*args)
  File "/.pyenv/versions/3.8.0/lib/python3.8/urllib/request.py", line 502, in _call_chain
    result = func(*args)
  File "/.pyenv/versions/3.8.0/lib/python3.8/urllib/request.py", line 649, in http_error_default
    raise HTTPError(req.full_url, code, msg, hdrs, fp)
urllib.error.HTTPError: HTTP Error 403: Forbidden

Another location and video:

[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['https://www.youtube.com/watch?v=WSg4sE0k5PY', '--verbose']
[debug] Encodings: locale UTF-8, fs utf-8, out utf-8, pref UTF-8
[debug] youtube-dl version 2020.03.24
[debug] Python version 3.8.2 (CPython) - Linux-4.15.0-76-generic-x86_64-with-glibc2.27
[debug] exe versions: ffmpeg 3.4.6, ffprobe 3.4.6
[debug] Proxy map: {}
[youtube] WSg4sE0k5PY: Downloading webpage
[youtube] {18} signature length 112, html5 player vflset
[youtube] {137} signature length 112, html5 player vflset
[youtube] {136} signature length 112, html5 player vflset
[youtube] {135} signature length 112, html5 player vflset
[youtube] {134} signature length 112, html5 player vflset
[youtube] {133} signature length 112, html5 player vflset
[youtube] {160} signature length 112, html5 player vflset
[youtube] {140} signature length 112, html5 player vflset
[youtube] {249} signature length 112, html5 player vflset
[youtube] {250} signature length 112, html5 player vflset
[youtube] {251} signature length 112, html5 player vflset
[debug] Default format spec: bestvideo+bestaudio/best
WARNING: Requested formats are incompatible for merge and will be merged into mkv.
[debug] Invoking downloader on 'https://r1---sn-p5qlsndr.googlevideo.com/videoplayback?expire=1586505050&ei=-tCPXsrIDYGL8gSCiZPIBw&ip=XXXXXXXX&id=o-AJXFGqURHkbncbkHOZnVpzWXvTPYURfZmEcRHte0LSB2&itag=137&aitags=133%2C134%2C135%2C136%2C137%2C160&source=youtube&requiressl=yes&mh=Gd&mm=31%2C26&mn=sn-p5qlsndr%2Csn-4g5edney&ms=au%2Conr&mv=m&mvi=0&pl=21&gcr=pe&initcwndbps=417500&vprv=1&mime=video%2Fmp4&gir=yes&clen=24271081&dur=395.200&lmt=1532365167617179&mt=1586483323&fvip=1&keepalive=yes&c=WEB&sparams=expire%2Cei%2Cip%2Cid%2Caitags%2Csource%2Crequiressl%2Cgcr%2Cvprv%2Cmime%2Cgir%2Cclen%2Cdur%2Clmt&lsparams=mh%2Cmm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps&lsig=ALrAebAwRQIgECeJEo-oiiBaUtBZYFsPl14gpJ8sh8ewHPMvPf2hOLMCIQC3R3DBRT042RhF5GTLSCsfor8gUGnzzZHRYxB7xI7HsA%3D%3D&sig=0PlLswRQIhAMrZsSSkdUkL8re3qUP5YX903K-RA8EHwP30X64Av8=pAiBkOvteovBv5844prqcReakbNlmmTosg3MLcRLfLpcG_A===888&ratebypass=yes'
ERROR: unable to download video data: HTTP Error 403: Forbidden
Traceback (most recent call last):
  File "/venv/lib/python3.8/site-packages/youtube_dl/YoutubeDL.py", line 1921, in process_info
    partial_success = dl(fname, new_info)
  File "/venv/lib/python3.8/site-packages/youtube_dl/YoutubeDL.py", line 1866, in dl
    return fd.download(name, info)
  File "/venv/lib/python3.8/site-packages/youtube_dl/downloader/common.py", line 366, in download
    return self.real_download(filename, info_dict)
  File "/venv/lib/python3.8/site-packages/youtube_dl/downloader/http.py", line 341, in real_download
    establish_connection()
  File "/venv/lib/python3.8/site-packages/youtube_dl/downloader/http.py", line 109, in establish_connection
    ctx.data = self.ydl.urlopen(request)
  File "/venv/lib/python3.8/site-packages/youtube_dl/YoutubeDL.py", line 2239, in urlopen
    return self._opener.open(req, timeout=self._socket_timeout)
  File "/.pyenv/versions/3.8.0/lib/python3.8/urllib/request.py", line 531, in open
    response = meth(req, response)
  File "/.pyenv/versions/3.8.0/lib/python3.8/urllib/request.py", line 640, in http_response
    response = self.parent.error(
  File "/.pyenv/versions/3.8.0/lib/python3.8/urllib/request.py", line 569, in error
    return self._call_chain(*args)
  File "/.pyenv/versions/3.8.0/lib/python3.8/urllib/request.py", line 502, in _call_chain
    result = func(*args)
  File "/.pyenv/versions/3.8.0/lib/python3.8/urllib/request.py", line 649, in http_error_default
    raise HTTPError(req.full_url, code, msg, hdrs, fp)
urllib.error.HTTPError: HTTP Error 403: Forbidden

Description

I understand you are used to seeing many 403 bug reports that are just throttling/client side/provider site issues. This is NOT a duplicate and only seems to be happening in certain videos with signatures. The videos are all available publicly without an account from my location.

I am experiencing this from multiple locations and environments. It is a new issue that I only started noticing in the last week and it is not consistent. If you attempt the same file over and over you will see mixed successes and errors.