February 20, 2019

Using LastPass in Pale Moon browser

Firefox 57 introduced a new extension API that broke most of the extensions I had been using, including It’s All Text, Dorando Keyconfig, and Tab Mix Plus. So I installed Pale Moon, a fork of an older Firefox that works with those extensions. But the current LastPass extension only works with the new (57+) Firefox.

A few months ago, I was able to find a copy of LastPass 3.3.4 on the Firefox web site; this is the last version that works with Pale Moon. Then today I tried to install Pale Moon on a second machine and discovered that LastPass 3.3.4 had been removed from the Firefox site, and I couldn’t find it anywhere else.

The solution was to recreate the xpi file for the extension using the existing installation. Here’s how to do that:

Pale Moon extensions are stored in ~/.moonchild productions/pale moon/xxxxxxxx.default/extensions/, where xxxxxxxx will be a seemingly random sequence of letters and digits. In that directory, the LastPass extension is stored in the subdirectory Move into that directory and then execute this command:

zip -r /tmp/lastpass.xpi .

Copy the resulting xpi file to /tmp on the second machine. In Pale Moon on that machine, enter this URL in the address bar:


The extension should install and be available upon restart of Pale Moon.