Are you using a password add-on/program?

In Firefox 63+ you can check the about:policies#active page to see what policies are active.

You can check if you have a policies.json file.

• https://support.mozilla.org/en-US/kb/customizing-firefox-using-policiesjson
• https://github.com/mozilla/policy-templates/blob/master/README.md

The policies.json file should be here:

• Firefox.app/Contents/Resources/distribution/policies.json

See also:

• https://support.mozilla.org/en-US/kb/managing-policies-osx-desktops
• https://support.mozilla.org/en-US/kb/customizing-firefox-macos-using-configuration-prof

- I don't use "password add-on" (I have default firefox lockwise) - I don't have "policies.json" file, actually I even don't have "distribution" directory. Inside "Firefox.app/Contents/Resources" I have following dirs: browser, defaults, en.lproj, gmp-clearkey, res. Should I create it? With what content? or should I just execute command, something similar to: sudo defaults write /Library/Preferences/org.mozilla.firefox OfferToSaveLogins -bool "true" - in "about:policies#active" the key "OfferToSaveLogins" is set to false

The other way to lock a preference externally is with an "Autoconfig" file. This involves two different files, as described in these articles:

• Customize Firefox using AutoConfig
• http://kb.mozillazine.org/Locking_preferences

If your computer is used in a managed environment such as a company, you should check with your IT before removing any policy or autoconfig files. If it's a home computer, hmm, why are those there?

On Mac it is possible to a plist file (org.mozilla.firefox.plist). This is similar to using GPO on Windows.

From:

• https://support.mozilla.org/en-US/kb/customizing-firefox-macos-using-configuration-prof

On MacOS, policy support is implemented using a properties list file or .plist file that can be configured to customize policies. You would need a special utility to inspect or edit a plist file.

• https://github.com/mozilla/policy-templates/blob/master/README.md