It works in 1.1.7.2(previous release of this addon) with the latest firefox version.
You can open download panel through toolbar.

It doesn't download anything. Useless.

sranje ne deluje

me encanta, lo mejor que he tenido en este tipo de app

This used to be an amazing tool, except since the latest release it no longer works. Please address this situation. I used to love this add-on.

Latest update doesn't work so I also had to download the previous version as well. Other than that, this is a great add-on that delivers.

Dear developer!

It hasn't converted to mp3 in a while after downloading videos. Native client installed, ffmpeg installed, browser settings unchanged. I didn't change anything and all of a sudden I stopped making mp3s. What could be the problem? Thanks :-)

This is generally an excellent product, but as others may have said, the latest version is for some reason not working (perhaps due to an update in YT's UI), but you can go back to the versions page and download an earlier version that appears to be working normally. I'm having good results with Ver 1.16.

not working again. not fixed. i guess it is dead and gone. will miss this app wish it would be fixed. nothing else worked as well as this

I have used this for Many Many years and it has been Great.

At the Moment Version 1.1.8 The Hour Glass either freezes or just keeps spinning.

Rolling back to 1.1.7.2 has fixed it, I was getting slow downloads for months with this version, but after quite a few attempts at completely removing and reinstalling, it now seems to be downloading properly again.

Clicking on download panel doesn't work, it just loads for hours

These are the hardest working devs on the Internet. I have been using this plugin forever, and it has worked 90% of the time. The other 10% is YouTube's fault for changing things up, but these guys are always on TOP of it, man. For now, going back to 1.1.6 will fix most of your issues, until they get to the new problems. Just go back to the main page, under "More Information" box, under "Version History" click on "See all versions" and find 1.1.6 and click that download link.

fix please :(

Latest version now freezes Firefox. Older versions no longer display the previous icon on YouTube and no longer download at fast speed and instead go at a crawling 50kb/s. This used to be my favourite YouTube downloader extension, but whether YouTube has changed something or the developers have screwed something up, this extension no longer is the only functional YouTube downloader, as they're all equally shit now. Such a shame.

Not working on version 96.

Updated to 1.1.8 and the panel does not freezes, but does not work. It seems to unable to detect media.

Stop functioning a couple of days ago

Big issue, It doesn't work with new version of firefox and it freezes every time I open Panel