Dear Support Team, I tried enabling localfilelinks in firefox and found this thread https://support.mozilla.org/fr/questions/1264779 which mentions creating a "user.js" file and adding this: / Create policy enabling http: or https: pages to link to file: user_pref("capability.policy.policynames", "filelinks"); user_pref("capability.policy.filelinks.checkloaduri.enabled", "allAccess"); // Sites to which the policy applies (protocol://hostname protocol://hostname) user_pref("capability.policy.filelinks.sites", "http://example.com http://intranet"); then reloading firefox. The fix worked and i was able to use local files in firefox. My Problem now is reverting localfileaccess to default (blocked). i tried modifying the "user.js", deleting it, deleting and reinstalling firefox, cleaning the firefox install and creating a new profile. when i deleted user.js the enabled options vanished from "prefs.js" but local file access was still enabled. I also tried to edit the generated options in about:config but i cannot get it to revert to localfile access beeing locked and couldn't find any way to fix my problem. Is there an easy way to relock this?