Assegnate 2 su 5 stelle

Can't install, get this message:

Firefox could not install the search plugin from "https://addons.mozilla.org/en-US/firefox/downloads/latest/12142/addon-12142-latest.xml?src=addondetail" because an engine with the same name already exists.

why?

Questa recensione riguarda una versione precedente (20090608) del componente aggiuntivo.