Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

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

My prefs.js file is being automatically rewritten every time FF loads

  • 3 பதிலளிப்புகள்
  • 1 இந்த பிரச்சனை உள்ளது
  • 1 view
  • Last reply by cor-el

My proxy settings are being changed every time FF loads, from Automatically Detected or No Proxy to Manual 127.0.0.1. In reading other articles I found the prefs.js file in my Profiles directory and deleted the two lines that reference a Proxy location as directed, as well as changed to the proxy.type setting to 0. Firefox is always closed when I do this. I reload FF and I'm right back to the Manual Proxy setting with the 127.0.0.1 address. The date/time stamp shows the prefs.js was edited at the same moment I reloaded FF, but obviously not by me, and the lines I deleted are right back in there.

These settings were fine forever. I got one of those fake anti-virus program scams on my system late last week, and this started happening then. However I've removed (or so I thought) all references to that program and it hasn't returned. Maybe a coincidence, maybe not.

Any help will be appreciated.

My proxy settings are being changed every time FF loads, from Automatically Detected or No Proxy to Manual 127.0.0.1. In reading other articles I found the prefs.js file in my Profiles directory and deleted the two lines that reference a Proxy location as directed, as well as changed to the proxy.type setting to 0. Firefox is always closed when I do this. I reload FF and I'm right back to the Manual Proxy setting with the 127.0.0.1 address. The date/time stamp shows the prefs.js was edited at the same moment I reloaded FF, but obviously not by me, and the lines I deleted are right back in there. These settings were fine forever. I got one of those fake anti-virus program scams on my system late last week, and this started happening then. However I've removed (or so I thought) all references to that program and it hasn't returned. Maybe a coincidence, maybe not. Any help will be appreciated.

All Replies (3)

See if you have a user.js file in your Profile folder.

http://kb.mozillazine.org/User.js_file

user.js is read after the prefs.js file is read, as Firefox is launched each time.

user.js is an optional file which doesn't come with Firefox, so "someone" added that file if it exists in your Profile. If you don't recall creating that file yourself, just delete it. Or if you did create that file and have a need for it, just edit out those two lines and save it.

I had looked for the user.js file and its nowhere to be seen in that directory (or anywhere else on my system--I checked just to be sure.)

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the extensions is causing the problem (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).