The add on has an explanation of how this works: [https://addons.mozilla.org/en-us/firefox/addon/r-kiosk/] It looks like it depends on a user.js file. Does this still exist in the profile? Javascript needs to be enabled. In Firefox 23, as part of an effort to simplify the Firefox options set and protect users from unintentially damaging their Firefox, the option to disable JavaScript was removed from the Firefox Options window. However, the option to disable JavaScript was not removed from Firefox entirely. You can still access it from about:config or by installing an add-on. '''about:config''' # In the address bar, type "about:config" (with no quotes), and press Enter. # Click "I'll be careful, I promise" # In the search bar, search for "javascript.enabled" (with no quotes). # Right click the result named "javascript.enabled" and click "Toggle". JavaScript is now disabled. To Re-enable JavaScript, repeat these steps. '''Add-ons''' You can alternatively install an add-on that lets you disable JavaScript, such as *[https://addons.mozilla.org/firefox/addon/noscript/ No-Script] (to disable JavaScript on a per page basis, as required) *[https://addons.mozilla.org/firefox/addon/quickjava/ QuickJava] (to easily disable and enable JavaScript, automatic loading of images, and other content) *[https://addons.mozilla.org/firefox/addon/settingsanity/ SettingSanity] (adds back removed options for JavaScript, Advanced JavaScript Settings, loading images, and showing the Tab Bar) Thank you, please reply back with the results. I also recommend updating to Firefox 30.