Doesn't do anything on Firefox 17 Puntuado con 1 de 5 estrellas

This add-on suddenly no longer works in Firefox 17. It simply doesn't show up any more in any of the status bars. It's just... gone. The add-in does nothing. (And to the reply by the developer below: No, this was specifically when the app was installed and active. Yes, I tried disabling it, reenabling it, and rebooting. Yes, I tried uninstalling and reinstalling it.I'm telling you, it's just GONE. It didn't appear near the address bar. It didn't insert an icon and menu near the video. And it wasn't on the context menu. It just wasn't anywhere. The only sign that it was even installed was the entry in Firefox Add-ons.)

Esta valoración es de una versión anterior del complemento (4.9.13.1-signed). 

If the addon does not appear anywhere, it's just that you uninstalled or disabled it. Not the addon fault anyway.