Video won't download? What to do

Websites change how they work all the time. Most problems are solved in a minute.

Steps

Update the site reader: Help → Update the site reader (yt-dlp), then try again.
Is it a live stream? Live streams aren't downloaded. Download the recording once the stream ends and is published.
Only for signed-in users? Send it from the browser extension and allow cookie access when the browser asks. The app uses them only for that download and does not keep them.
Still not working? Help → Save a problem report, then report the problem. Reports are public: don't include passwords or personal data.

Videos protected with DRM (paid streaming services) can't be downloaded. That's intentional.
Check that the link opens and plays in the browser.

Video Download is free for Windows and Mac.