I'm trying to setup a Mozilla.cfg file to lock down the installation of themes and extensions.

I have a config file that I've been working on and has been blocking a lot of what we don't want our organization to do, however I am unable to get it to block the installation of themes to Firefox.

I have both:

lockPref("xpinstall.enabled" ,false);


lockPref("config.lockdown.disable_extensions", true);
lockPref("config.lockdown.disable_themes", true);

the ability to install extensions are locked down, however the user is still able to install themes from Mozilla Addons

  • Are extensions and addons not the samething? – Ramhound Oct 27 '14 at 13:20
  • @Ramhound, they are... Mozilla refers to addons as both extensions and themes. When you go to that addons site, the ability to install extensions is blocked (using the options above) however I'm trying to block the ability to install themes. – Phonic Oct 27 '14 at 13:23

Try to apply the settings from Firefox UI and, check the configuration file and note down the configuration changes.

Try the settings provided by firefox to disable or remove the extensions and themes. All settings are detailed in the below link.


Hope this helps.

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