subtites don't convert if I do --skip-download (youtube)

[KoleckOLP]

• I'm reporting a broken site support issue
• I've verified that I'm running youtube-dl version 2019.10.22
• 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

C:\Program Files (x86)\1. NoInstall\yt-dl>youtube-dl.exe -v --write-sub --write-auto-sub --convert-subs srt "https://www.youtube.com/watch?v=8VYV_hY4C0o"
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['-v', '--write-sub', '--write-auto-sub', '--convert-subs', 'srt', 'https://www.youtube.com/watch?v=8VYV_hY4C0o']
[debug] Encodings: locale cp1250, fs mbcs, out cp852, pref cp1250
[debug] youtube-dl version 2019.10.22
[debug] Python version 3.4.4 (CPython) - Windows-10-10.0.18362
[debug] exe versions: ffmpeg 4.2
[debug] Proxy map: {}
[youtube] 8VYV_hY4C0o: Downloading webpage
[youtube] 8VYV_hY4C0o: Downloading video info webpage
[youtube] 8VYV_hY4C0o: Looking for automatic captions
[debug] Default format spec: bestvideo+bestaudio/best
[info] Writing video subtitles to: FluttERR MLH-8VYV_hY4C0o.en.vtt
WARNING: Requested formats are incompatible for merge and will be merged into mkv.
[debug] Invoking downloader on 'https://r3---sn-jv2gvntn-2gbe.googlevideo.com/videoplayback?expire=1572193899&ei=CnK1XZ6WNIe5gAei85L4CQ&ip=77.104.213.44&id=o-AB2pbMYqIjndAT_y_iF4A8cWGSggXWIu7R5hwZejV-oz&itag=136&aitags=133%2C134%2C135%2C136%2C160%2C242%2C243%2C244%2C247%2C278&source=youtube&requiressl=yes&mm=31%2C29&mn=sn-jv2gvntn-2gbe%2Csn-2gb7sn7z&ms=au%2Crdu&mv=m&mvi=2&pl=18&initcwndbps=903750&mime=video%2Fmp4&gir=yes&clen=30678088&dur=331.164&lmt=1537001232792333&mt=1572172223&fvip=3&keepalive=yes&fexp=23842630&c=WEB&sparams=expire%2Cei%2Cip%2Cid%2Caitags%2Csource%2Crequiressl%2Cmime%2Cgir%2Cclen%2Cdur%2Clmt&sig=ALgxI2wwRQIgKSNZWNhYKDA_VAvFdFIN7dTUJ1v1KUY19LjMhsGXa7MCIQCTtf5QgmN9kuYQRVXM3LDPpVTGSadxgnpRToV0iPlDxg%3D%3D&lsparams=mm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps&lsig=AHylml4wRAIgYnEzQBis5YYmVebkl1Q6U-rxWUtYIxXh64rdqumb1AUCIDQZk2sj3c7ouM3Z6IYcApOEKkm8t06XQDcFcUC1bqTq&ratebypass=yes'
[download] Destination: FluttERR MLH-8VYV_hY4C0o.f136.mp4
[download] 100% of 29.26MiB in 00:43
[debug] Invoking downloader on 'https://r3---sn-jv2gvntn-2gbe.googlevideo.com/videoplayback?expire=1572193899&ei=CnK1XZ6WNIe5gAei85L4CQ&ip=77.104.213.44&id=o-AB2pbMYqIjndAT_y_iF4A8cWGSggXWIu7R5hwZejV-oz&itag=251&source=youtube&requiressl=yes&mm=31%2C29&mn=sn-jv2gvntn-2gbe%2Csn-2gb7sn7z&ms=au%2Crdu&mv=m&mvi=2&pl=18&initcwndbps=903750&mime=audio%2Fwebm&gir=yes&clen=6105314&dur=331.221&lmt=1537002530997481&mt=1572172223&fvip=3&keepalive=yes&fexp=23842630&c=WEB&sparams=expire%2Cei%2Cip%2Cid%2Citag%2Csource%2Crequiressl%2Cmime%2Cgir%2Cclen%2Cdur%2Clmt&sig=ALgxI2wwRAIgZbpKE8640p9fokR__hcFo-dBNvrOrij5u1gbxEw5k8wCIEyyDViQwT6sdUVsDB4YyANJjU0XXt_hFyAAsjZDG9M8&lsparams=mm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps&lsig=AHylml4wRAIgYnEzQBis5YYmVebkl1Q6U-rxWUtYIxXh64rdqumb1AUCIDQZk2sj3c7ouM3Z6IYcApOEKkm8t06XQDcFcUC1bqTq&ratebypass=yes'
[download] Destination: FluttERR MLH-8VYV_hY4C0o.f251.webm
[download] 100% of 5.82MiB in 00:08
[ffmpeg] Merging formats into "FluttERR MLH-8VYV_hY4C0o.mkv"
[debug] ffmpeg command line: ffmpeg -y -loglevel "repeat+info" -i "file:FluttERR MLH-8VYV_hY4C0o.f136.mp4" -i "file:FluttERR MLH-8VYV_hY4C0o.f251.webm" -c copy -map "0:v:0" -map "1:a:0" "file:FluttERR MLH-8VYV_hY4C0o.temp.mkv"
Deleting original file FluttERR MLH-8VYV_hY4C0o.f136.mp4 (pass -k to keep)
Deleting original file FluttERR MLH-8VYV_hY4C0o.f251.webm (pass -k to keep)
[ffmpeg] Converting subtitles
[debug] ffmpeg command line: ffmpeg -y -loglevel "repeat+info" -i "file:FluttERR MLH-8VYV_hY4C0o.en.vtt" -f srt "file:FluttERR MLH-8VYV_hY4C0o.en.srt"
Deleting original file FluttERR MLH-8VYV_hY4C0o.en.vtt (pass -k to keep)

C:\Program Files (x86)\1. NoInstall\yt-dl>youtube-dl.exe -v --write-sub --write-auto-sub --convert-subs srt --skip-download "https://www.youtube.com/watch?v=8VYV_hY4C0o"
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['-v', '--write-sub', '--write-auto-sub', '--convert-subs', 'srt', '--skip-download', 'https://www.youtube.com/watch?v=8VYV_hY4C0o']
[debug] Encodings: locale cp1250, fs mbcs, out cp852, pref cp1250
[debug] youtube-dl version 2019.10.22
[debug] Python version 3.4.4 (CPython) - Windows-10-10.0.18362
[debug] exe versions: ffmpeg 4.2
[debug] Proxy map: {}
[youtube] 8VYV_hY4C0o: Downloading webpage
[youtube] 8VYV_hY4C0o: Downloading video info webpage
[youtube] 8VYV_hY4C0o: Looking for automatic captions
[debug] Default format spec: bestvideo+bestaudio/best
[info] Writing video subtitles to: FluttERR MLH-8VYV_hY4C0o.en.vtt

I am trying to download subtitles from youtube without downloading the video and convert them to srt

this only works if I also download the video

[KoleckOLP]

Can I see the post mine is a duplicate off?