This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Firefox 17 had a mozilla.cfg file which we could customize proxy and other settings with. Now in Firefox 18 it is gone. How can I customize these settings?

  • 4 replies
  • 5 have this problem
  • 1 view
  • Last reply by Mase2k

more options

I have just finished getting my domain of 18 Terminal Servers online with Firefox 17. I configured their Mozilla.cfg files for proxy and Kerberos authentication settings and everything was working great. One site updated to Firefox 18 and now nothing is working. Come to find out 18 no longer integrates the use of the Mozilla.cfg file? Please help!

I have just finished getting my domain of 18 Terminal Servers online with Firefox 17. I configured their Mozilla.cfg files for proxy and Kerberos authentication settings and everything was working great. One site updated to Firefox 18 and now nothing is working. Come to find out 18 no longer integrates the use of the Mozilla.cfg file? Please help!

All Replies (4)

more options

This should still be working.

Did you check for errors or no longer supported pref settings in the mozilla.cfg file?

Also make sure that the .js file in defaults\pref to include the mozille.cfg file is still present.


Place a file local-settings.js in the defaults\pref folder where you also find the file channel-prefs.js to specify using mozilla.cfg.

pref("general.config.filename", "mozilla.cfg");
pref("general.config.obscure_value", 0); // use this to disable the byte-shift

See:

You can use these functions in mozilla.cfg:

defaultPref();  // set new default value
pref();         // set pref, but allow changes in current session
lockPref();     // lock pref, disallow changes
more options

Thank you for your quick response. I find it strange that in 17 I did not require anything in defaults\pref in order to make use of the mozilla.cfg file. Was this a new change with 18? Does it matter that the version of 17 I am running says "Firefox ESR" and the version of 18 does not?

more options

Hi, please check if it is only a mozilla.cfg problem: try to manually configure proxy and authenticatoin on one client running firefox 18 and see if it is working.

I think there is an issue with firefox 18+authenticated proxy : i am investigating for narrowing down the problem and looking for a workaround.

Regards mrc2k

more options

mrc2k,

    Firefox 18 did not even come with mozilla.cfg which leads me to believe that the version of 17 ESR is why I was having such success with altering the mozilla.cfg file. I believe I may have resolved my own query but will not know until later when I can load 17 ESR on the problem server. Thank you for your reply.