404 error for fragments on youtube videos

[mzso]

Checklist

• I'm reporting a broken site support issue
• I've verified that I'm running youtube-dl version 2020.01.24
• 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

output.txt

Description

For a while now (months) I get 404 errors and fragment retries. And rather slow downloads because of this.
Today I noticed that fragments are sometimes actually skipped after 10 retries. I'm not sure what that means. Will the video actually be missing parts? Ouch.
I didn't notice whole fragments being skipped and downloads failing until recently. Not sure why it started happening.

Strangely I didn't see an issue opened that seems relevant.

[dstftw]

Most likely intermittent youtube issue.

[mzso]

@dstftw commented on null:

Most likely intermittent youtube issue.

Intermittent? I guess it depends how you look on it. It seems to happen rather often. The video I tested with produced the error several times. Got interrupted several times. And it couldn't even be finished because merging failed partway through.