Firefox uses the "chrome://" protocol to access its internal files and use chrome in other cases like userChrome.css (no relation with Google Chrome). *https://developer.mozilla.org/en-US/Chrome ---- You can create a new profile as a quick test to see if your current profile is causing the problem. See "Creating a profile": *https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems. *https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile ----- Try the Firefox version from the official Mozilla server if you currently use a version from the repositories of your Linux distribution. *https://www.mozilla.org/en-US/firefox/all/#product-desktop-release