Repository: youtube-dl
Issue: youtube extractor raises DRM protected errors when extracting empty playlists
Labels: cant-reproduce,incomplete

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## Checklist

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Carefully read and work through this check list in order to prevent the most common mistakes and misuse of youtube-dl:
- First of, make sure you are using the latest version of youtube-dl. Run `youtube-dl --version` and ensure your version is 2021.12.17. If it's not, see https://yt-dl.org/update on how to update. Issues with outdated version will be REJECTED.
- Make sure that all provided video/audio/playlist URLs (if any) are alive and playable in a browser.
- Make sure that all URLs and arguments with special characters are properly quoted or escaped as explained in http://yt-dl.org/escape.
- Search the bugtracker for similar issues: http://yt-dl.org/search-issues. DO NOT post duplicates.
- Read bugs section in FAQ: http://yt-dl.org/reporting
- Finally, put x into all relevant boxes (like this [x])
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- [ ] I'm reporting a broken site support issue
- [x] I've verified that I'm running youtube-dl version **2021.12.17**
- [ ] I've checked that all provided URLs are alive and playable in a browser
- [x] I've checked that all URLs and arguments with special characters are properly quoted or escaped
- [x] I've searched the bugtracker for similar bug reports including closed ones
- [x] I've read bugs section in FAQ


## Verbose log

<!--
Provide the complete verbose output of youtube-dl that clearly demonstrates the problem.
Add the `-v` flag to your command line you run youtube-dl with (`youtube-dl -v <your command line>`), copy the WHOLE output and insert it below. It should look similar to this:
 [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 2021.12.17
 [debug] Python version 2.7.11 - Windows-2003Server-5.2.3790-SP2
 [debug] exe versions: ffmpeg N-75573-g1d0487f, ffprobe N-75573-g1d0487f, rtmpdump 2.4
 [debug] Proxy map: {}
 <more lines>
-->

```
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['-v', 'https://www.youtube.com/playlist?list=VLPLdZmvfk6Qqb7PFtsqGqNQ4804xSTX2dlF']
[debug] Encodings: locale UTF-8, fs utf-8, out utf-8, pref UTF-8
[debug] youtube-dl version 2021.12.17
[debug] Git HEAD: cf1105f
[debug] Python 3.10.4 (CPython x86_64 64bit) - Linux-6.3.9-arch1-1-x86_64-with-glibc2.37 - OpenSSL 3.1.1 30 May 2023 - glibc 2.37
[debug] exe versions: ffmpeg 6.0, ffprobe 6.0
[debug] Proxy map: {}
[youtube:tab] VLPLdZmvfk6Qqb7PFtsqGqNQ4804xSTX2dlF: Downloading webpage
[download] Downloading playlist: VLPLdZmvfk6Qqb7PFtsqGqNQ4804xSTX2dlF
[youtube:tab] Downloading page 1
[youtube:tab] Downloading page 2
[youtube:tab] Downloading page 3
[youtube:tab] Downloading page 4
[youtube:tab] Downloading page 5
[youtube:tab] Downloading page 6
[youtube:tab] Downloading page 7
[youtube:tab] Downloading page 8
[youtube:tab] Downloading page 9
[youtube:tab] Downloading page 10
[youtube:tab] Downloading page 11
[youtube:tab] playlist VLPLdZmvfk6Qqb7PFtsqGqNQ4804xSTX2dlF: Downloading 268 videos
[download] Downloading video 1 of 268
[youtube] t7-XtJ0O1o8: Downloading webpage
[youtube] t7-XtJ0O1o8: Downloading MPD manifest
WARNING: Failed to download MPD manifest: HTTP Error 404: Not Found
ERROR: This video is DRM protected.
Traceback (most recent call last):
  File "/home/amar/Documents/dev/ytdl-testing/.venv/lib/python3.10/site-packages/youtube_dl/YoutubeDL.py", line 825, in wrapper
    return func(self, *args, **kwargs)
  File "/home/amar/Documents/dev/ytdl-testing/.venv/lib/python3.10/site-packages/youtube_dl/YoutubeDL.py", line 846, in __extract_info
    ie_result = ie.extract(url)
  File "/home/amar/Documents/dev/ytdl-testing/.venv/lib/python3.10/site-packages/youtube_dl/extractor/common.py", line 535, in extract
    ie_result = self._real_extract(url)
  File "/home/amar/Documents/dev/ytdl-testing/.venv/lib/python3.10/site-packages/youtube_dl/extractor/youtube.py", line 2100, in _real_extract
    raise ExtractorError(
youtube_dl.utils.ExtractorError: This video is DRM protected.
```


## Description

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Hey guys :)

I didn't check checklist items 1 or 3 since they don't seem applicable to this small issue. The extractor is not broken and works and in this instance there are no actual playable songs/videos, since I'm trying to "extract" an empty playlist.

So this is more so to report *potentially* incorrect exception messages (since there isn't any DRM protected content in the playlist). It looks like the YouTube extractor makes an incorrect assumption and throws a `DownloadError: ERROR: This video is DRM protected` when trying to extract an empty public playlist.

Here's a link to the empty public playlist for reference:
https://www.youtube.com/playlist?list=VLPLdZmvfk6Qqb7PFtsqGqNQ4804xSTX2dlF

Apologies if this issue makes more sense as a feature request, I wasn't sure if this was intended behavior or not so thought I would post it as a bug report.