TO FIX THE PROBLEM, I went back to version 1.1.6 which also uses the older detection algorithm and that works great for me (five stars great). Other users may want to do the same until the bugs are worked out of the latest release. On the options page for this extension, I set "Allow automatic updates" to OFF since I don't want 1.1.6 to be replaced by that buggy new version. Once the bugs are fixed, I'll set it back to the Default value again.

The older 1.1.6 version was obtained by going to the bottom left side of the Firefox Add-On page for this extension. You see a clickable link to See All Versions.

If you only get the spinning hourglass, check if you're running version 1.1.7, if so, just downgrade to 1.1.6 again

Not working anymore.

1.1.7.2 is not working. 1.1.6 is the last version that worked.

1.1.5 work

*EDIT

This is still the best app for downloading videos from Youtube!! It did not work for a while but I want to thank the author for his hard work making it work again!! You are the man!!

Ele não está funcionando com a versão 96.0.3 (64 bits) do Firefox.
Antes disso a minha avaliação é 5, mas sem funcionar... tem que ser apenas 1

1.2.1 not working any more. hope you gonna fix it

@Dishita, even if the extension is not working right now, I still give it 5 stars. No other extension is working right now (for free anyways) and yours have demonstrated in the past to be the best, and offer first a solution (for free again). I wish I could support you, I hope others are.

Now 1.1.8 is off the available versions and i can confirm 1.1.7.2 with Firefox 96.0.2 Linux Mint all is now working hunky doory doo :) Thanks Feller .. now i can once again put a 5* on this great extension. Thank you.

Funktioniert nicht mehr

--- January 27, 2022 ---
The problem that the screen freezes when the download panel is displayed is occurring again.
At this time, the only solution to this problem is to revert to version 1.6 or earlier.
The download speed will be greatly reduced, but let's accept it as it can't be helped now.

--- January 21, 2022 ---
The button under the player is hidden again, but it is possible to call the download panel from the button in the toolbar of the browser.
If the download panel doesn't finish loading, lowering the version to 1.1.7.2 may help.
By the way, the download speed issue has also been resolved since 1.1.7.2.

(The above is a translation of Japanese into English using Google Translate.)

The developer must be asleep. I had to revert to 1.1.5 to get the app to work. Why he broke the app and has not fixed it is beyond me. I turned off automatic updates for the app.

Mysteriously, the app updated itself even though I had turned updates off. Naturally, it quit working. It seems very resistant to having 1.1.15 installed and you have to be quick so it does not auto update. I had to try three times this time to get it to install.

I would like to know what the developer is doing!

estaba funcionando bien pero la actualizaron y ahora no sirve nada, estoy a punto de mejor desinstalarla

Siempre me ha gustado esta extension pero ultimamente no ha estado muy eficiente. No esta bajando los videos y no se cual es el problema.

One of the BEST and MOST CRUCIAL Firefox addons EVER! Happily using for years!
(Especially now that recent problems have been fixed.)

not working

beautiful app!!! thank you. But 1.1.8 doesnt work..when older ones yes!!!!