HTTP Error 503: Service Unavailable: Back-end server is at capacity

[Hackzzila]

I keep getting this error while trying to test my bot, full error

youtube_dl.utils.DownloadError: ERROR: Unable to download JSON metadata: HTTP Error 503: Service Unavailable: Back-end server is at capacity (caused by <HTTPError 503: 'Service Unavailable: Back-end server is at capacity'>); please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; see  https://yt-dl.org/update  on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.

[dstftw]

Post the full output of youtube-dl when run with -v, i.e. add -v flag to your command line, copy the whole output and post it in the issue body wrapped in ``` for better formatting. It should look similar to this:

$ youtube-dl -v <your command line>
[debug] System config: []
[debug] User config: []
[debug] Command-line args: [u'-v', u'http://www.youtube.com/watch?v=BaW_jenozKcj']
[debug] Encodings: locale cp1251, fs mbcs, out cp866, pref cp1251
[debug] youtube-dl version 2015.12.06
[debug] Git HEAD: 135392e
[debug] Python version 2.6.6 - Windows-2003Server-5.2.3790-SP2
[debug] exe versions: ffmpeg N-75573-g1d0487f, ffprobe N-75573-g1d0487f, rtmpdump 2.4
[debug] Proxy map: {}
...

Do not post screenshots of verbose log only plain text is acceptable.

The output (including the first lines) contains important debugging information. Issues without the full output are often not reproducible and therefore do not get solved in short order, if ever.

[Hackzzila]

The problem is that I am not directly using it, I am going through a library (discord.py) that uses it, the library developer wasn't much help.

[dstftw]

No help is possible without context, i.e. verbose log.