How can I record it?
Downloading is preferable to recording, but you can record with a screen-recorder If downloading fails.
In firefox, I use
- "DownloadHelper" (v4.9.22) installs an entry to the rt-click menu.
- "Flash and Video Download" (v1.58) can display a button on a toolbar (dark square with white down-arrow; adds a blob when there's a video). On youtube it'll list all all the available resolutions/file-types and their sizes.
Timing is important - if you wait too long after opening a page, the download link can disappear; if so, reload the page.
I also use "Flashblock" which might have some effect on the others - sometimes you need to start the video to DL, other times not....?
Edit: how about an example URL you want to DL and I'll see if I can get it ...?
Mint 17.3 Xfce/fluxbox/pulse-less - Xubuntu 15.10/fluxbox/pulse-less
Please edit your original post title to include [SOLVED] if/when it is solved!