I don't download a lot of video, so a download manager is a low priority - unless a want to download something.
For audio files, I capture the stream coming through the soundcard so no need.
I was using Free Download Manager. Nothing special, I probably only understood a fraction of what it could do - but it did what I wanted and downloaded videos fast and tagged a new filename to any duplicates, which was very handy.
For various reasons not fully understood, this program is no longer compatible with Firefox - or at least not my Firefox and the other people I found that were suddenly having the same problem wit a program that worked one day and was busted up the next.
I downloaded Orbit download manager, somehow tricking myself into thinking that this was an 'official' add-on. (I know all the add-ons carry some risk.)
Big mistake. Turns out that this 'download manager' - which I never even had a chance to actually use - automatically over-rides even custom 404 error pages and redirects users to Orbit link spam page. I had a problem with one of my pages, and instead of my 404, I wound up on Orbit.
At any rate, I uninstalled the program, then tried to hunt down any remaining folder or files. Couldn't find anything, and the problem was eliminated.
I need a new download manager for quick downloads of video files. Reputable suggestions?