I like that someone continued this to remove the Legacy label! My only concern so far are:

1. The download icon is invisible (but clicking it will work). I'm currently with the new YouTube interface (the one that lets you have a Dark theme), and I remember the Legacy version already fixed that. Please fix it :)

2. In this version, there's no label for the 60fps version of the video, the Legacy version had those labels :) Please update the icons for the 60fps videos since it confuses me a bit.

Those two are my only concerns, if those two are fixed, then I'd happily give it a 5 Star rating :D Really glad someone continued this because this add-on/extension is ultimately the best downloader for YouTube videos. I don't want to go through the cmd with youtube-dl to be honest, and this one just does it in one click! So please do fix the two things I mentioned :)

I would actually give this add-on 10 stars, if it were the legacy version - the "old" one. But I was surprised with the notification of this one when I opened the browser this morning, and there was no Options page, no Button, and thank god I still had the other one installed. So, I tried the old one with a YT vid. song, and it worked beautifully. I disabled it, restarted my browser, and there still wasn't a button for this one, so it was useless to me. I checked to see if it was hiding in customization. Nothing. I used the legacy version 2-3 times a week, all the time, and never a problem one. It was perfect. I can see from the other reviews here, that I am one of MANY with the exact same problem. I do not know what to do now. I am using FF56. I hope this is resolved quickly. This whole transition has been a nightmare, and I need this. I'll probably end up going to Chrome like everyone else. Countless people are already packing their bags, as I write this. It is truly a shame. Thank you for a fantastic add-on - THE OLD ONE - though. I loved it.

Although works, is simple enough to use well.
The only downside I miss some functionality.
Currently there is no way to prefer or not prefer certain formats.
I'm trying to get webm files with VP9 and would like the addon to list those first.
Also when finding a duplicate, the addon should prompt me and ask me what to do.
Presenting three options: cancel, overwrite and add under different name.

The old version let me do what I want to do, which is download the video and the extracted audio. It also REMEMBERS where I last saved a video/audio combination, so I don't have to keep traipsing around my hard drive to find the place to download.

WHY would you take a perfectly good program and break it so that it is only useful to complete tech-heads? It was fine before. It did what needed to be done. I have fiddled with this new version for about an hour now. I am done. GDit. I am so tired of having to go find alternate versions of things after the good version is broken by "improvements." What is wrong with "you people"?

The instructions say:
1. After installation, go to the options page and
-> 1. Install the native client (This is a small NodeJS client written by @andy_portmen)
-> 2. Install the FFmpeg executable
2. FFmpeg integration is required if high resolution video or audio files are preferred.
My questions are:
Where do I find the options page?
What is FFmpeg integration and how is it done?

Just as with the original, it is unclear from the configuration settings, what "you will get" upon choosing a download: a video-only file, an audio-only file, or a video with audio.

With the original, I know have it configured so that downloading a YouTube video delivers an mp4 video+audio and an mp3 audio-only. This is perfect, though I have not the foggiest which magical combination of unclearly worded settings gave me this wonder.

With the new WebFail version, I can not get the same result (video+sound, and audio). But worse, whatever setting I try, it downloads a video fail, then extracts an audio file, then deletes the video file under my eyes.

does what it claims,unlike others..

I downloaded and installed the extension. The instructions said to download an additional file from the options page. What options page? Where am I supposed to find it? There are no options given on the Firefox Add-on page. The old add-on worked great, this one doesn't work at all without an external file I can't seem to find. Also, I see lots of questions on this page, and no response whatsoever from the developer. So . . . the Add-on doesn't work and the developer doesn't respond. Why in the world would anyone want to deal with this nonsense?

Easy access, quick to learn, always works.

I'm glad that a new non-legacy version of this extension is available. I got everything to work, including adding the path to ffmpeg. Everything works like in the previous add-on. However, there's only 1 thing this one is missing: hiding filetypes of the available video downloads. I never use 3gp or WebM filetypes. I was able to hide these in the old add-on. Now these add extra "cluster" to the filetypes to download inside the video. Not a deal breaker, just extra annoyance over the old one.

The new version works good. But I can't find the download button which is the arrow button beneath the youtube vedio. there is just hollow space but it works anyway when I click hollow space.

Is there any way to set download directory before I download video? I try to set directory on setting but it doesn't work.

Liked the old version better. was much easier and it used to download both video and audio files when I click. can't find how to get it work this was again no matter how hard i try.

Best addon when it comes to downloading YouTube videos. However, it requires you to download external files to make it fully functional.

:(

This is very useful addon for me.
thanks

Cannot detect url_encoded_fmt_stream_map or adaptive_fmts.
Trying to download 3xbVuuxnJbg.
Hope You can fix it

Excellent add-on, and compatible with the new Firefox 57+ technology too... I agree with Rahoul, this is the last YouTube downloader you will try, there is no need to continue searching. I can't realize living without this gem. :-)

Tried a dozen of YT downloaders for Firefox. There was just one that was close to this one, but not close enough.