Just to get the most information, the addon was added to your browser? I've just tested installing and adding. And it's showing on my toolbar.

I'd suggest removing the add-on and re-installing. Perhaps there was a failed update.

The Last Pass extension is installed in my Fire Fox browser. The Last Pass icon did not respond, since the Fire Fox update, to single or double clicks so I removed the existing Last Pass extension and downloaded and installed a new extension, 4.1.54. There's still no response when the Last Pass icon is clicked.

I just clicked on the Last Pass icon and, voila, it asked for my password and then opened up for use. Whew!!!

Dammit! Last Pass did NOT open this morning when I clicked on the icon. It looks like a change in my default browser may be necessary.

After installing reinstalling and even a system restore I have icon for Last Pass at first I filled in login but I can't click on the icon. Now I can't fill in login information. I'm done I paying for Lass Pass and I can't use it. I am so frustrated I'm done. Maybe in six months I'll come back to see if Mozilla has their crap together I can't do this anymore... this is just ridiculous.

If my understanding is correct, FF update 57 is due on 11/14/17 and will solve the Last Pass problem. If it doesn't l will have to go to Edge or IE permanently.

Come on, Mozilla! Let's get it right!!!

I downloaded Firefox Quantum, version 57.0 this morning and thank goodness my Last Pass icon now responds when clicked.