For those having trouble downloading LastPass -- go to settings; Help; About -- you either need to click "Restart to update Firefox" or there is a new Firefox update for you to download.

If LastPass doesn't work any longer: download and install the latest version of Firefox.
Si LastPass ne fonctionne plus ("Échec du téléchargement. Veuillez vérifier votre connexion"), installe la dernière version de Firefox.
Falls LastPass nicht mehr funktioniert: installiere die neuste Firefox-Version.