Firefox Community Forum

For a long time I've used Firefox on Linux with multiple instances each with their own profile folder. Today when I try to run these instances with separate profile folders I get the following error:

> Firefox is already running, but is not responding. To use Firefox, you must first close the existing Firefox process, restart your device, or use a different profile.

Profiles are created like this:

firefox --new-instance --createprofile "PROFILENAME ~/.firefox-PROFILENAME"

They are run like this:

firefox --new-instance --profile "~/.firefox-PROFILENAME"

It seems something has broken with the instance isolation as this is now throwing an error. Additionally I run "createprofile" it doesn't seem to actually create the folder.

Hello!

I'm writing because I cant seem to import my old profile using this [tutorial]. I have followed it thoroughly, and every time I open firefox its still the same default page that you get when u first download the browser.

I have downloaded and installed Mozilla Firefox on a new computer through the Edge browser both from the Mozilla site and through the Microsoft store. The installation downloads and installs as it should. Firefox has been selected as the default browser and everything appears as it should. When I open Firefox and type in an address, nothing populates. No site will open on the screen. When I open settings in Firefox, nothing opens. When I open history, it shows that I have been to the sites that I have loaded even though they haven't shown on the browser. I have completely uninstalled Firefox and reinstalled it with the same result. I have downloaded Opera browser and it installs correctly, I have downloaded and installed Firefox from Opera and had the same result. Any ideas?

Thanks, John

I have migrated from old MacPro to new Mac Studio. Firefox ESR version 115.9 has migrated with it. I've downloaded the latest Firefox but it operates independently of the ESR version. How do I ensure new version has all log in, contacts and history?

It has been observed that when a user uses the Firefox browser and tries to download a DDD file, the file format is .pdf instead of .ddd. In the devtools, it was observed that the content-type is text/plain in the response to the request. I changed the content-type to application/octet-stream, but the error still persists

ERROR MESSAGE WHEN TRYING TO ACCESS ALL WEB SITES: Secure Connection Failed

An error occurred during a connection to connect.xfinity.com. PR_END_OF_FILE_ERROR

Error code: PR_END_OF_FILE_ERROR

The page you are trying to view cannot be shown because the authenticity of the received data could not be verified. Please contact the website owners to inform them of this problem. Learn more

I am running version 125.0.3 (64-bit) on Windows 11, and I can't check for updates and have to manually download each new version after given a popup telling me that the latest Firefox update couldn't be installed. I've tried restarting the computer, tried running the Mozilla Maintenance Service, and installing the latest updates for Firefox and Windows 11. Nothing I've tried has worked, and no other help article has helped me thus far.

I have an older piece of equipment that I need to communicate with it and the 232 interface will only work through Firefox. I was told I can downgrade the current version to 3.0, which is what I need, but I cannot find out how. HELP

Jeff

I am running macOS 10.15.7 and Firefox won't upgrade past ESR v. 115 to the "regular" version 127.

Alternately, downloading the Firefox v. 127 installer and running won't update ESR v. 115 nor will it import bookmarks or data from the previous version ESR 115. Firefox v. 127 installs and starts as if I am a new user without any update or import option so that all previous settings, passwords, and data from ESR v. 115 are lost.

Is there a work-around for the upgrade to keep continuity, settings, bookmarks, and data when migrating to v. 127? Thanks!

After updating a W10 laptop from 115 to 116 of FF the user started having problems with getting to different websites (sites they worked on/with regularly). The problem is the cert DB. The doc I found says that it is cert8.db. Actually it is now cert9.DB.

What I had to do was go to task manager and kill a task that was holding the cert9.db file. Then I could rename it (cert9.old.db). Then restarted their laptop and FF came up and started fixing the cert file (as expected). This seems to have fixed their problem.

On Mac OS 14.4 Firefox hangs on launch and crashes, requiring "Force Quit" when I try to Refresh or Troubleshoot. Uninstalled and reinstalled multiple times, and restarted computer several times. Have spent several hours trying multiple community suggestions to now avail.

I am not a programmer, but am able to follow instructions. I clearly need someone to hold my hand and walk me through the solution. (I even checked out the Kaspersky suggestion, but cannot install it because Firefox cannot connect to the Internet.)

I have downloaded and saved "Raw Data.docx" and "Application Basics tex.docx" from one of the crash reports.

P.S. On this question form Firefox guessed that my operation system was Mac OS x 10_15_7, but it is 14.4

Julian

Hi, I keep getting this error when I try to download any extension. I also get an automatic download fail as soon as I try to download anything. I have tried several solutions such as changing privileges to reinstalling firefox entirely. I have checked other browsers on my computer and it is just firefox.

I wish to export, and not copy, a digital certificate so that I can import it to Keychain on my Mac. The only option in Firefox Browser on Mac is to copy, which means it only opens as a TextEdit and cannot be imported.

Any recommendations?

I want to create a link in the bookmarks toolbar to easy check and update firefox In chrome I can do that with creating a bookmark to: chrome://settings/help In edge I can do that with creating a bookmark to: edge://settings/help I have search for, but cannot find the equivalent in firefox

I changed computers. I installed Firefox. I followed these directions:

Back up and restore information in Firefox profiles https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

I copy the contents of the profile folder from the old computer to the new profile folder on the new computer. I opened Firefox and my bookmarks and Add-Ins were not restored. I manually imported my bookmarks from a backup and got them restored. How do I restore my Add-ins and all their settings and configuration files?

Why did that profile files restoration restore my bookmarks and Add-Ins?

Thanks to anybody who can help me.

Trying to download nord vpn and is says "failed" tried to download a receipt for the purchase of above and it says "failed" the browser on Win 10 is set to save files to downloads

It looks as though installing this 115.10 ESR will be a "new Install" instead of an update.

1) Will I lose my bookmarks, settings, passwords, ect? (My bookmarks have been collecting for years....)

2) If I try this will creating a restore point return me back to the way I was before the attempt?

Thank You All!

Fx 124.0

Why am I getting these notifications? I have the latest version, but this prompt not only asks me to update, but there's no mention that it will install the beta 125.0 beta 1

I started getting "can't load XPCOM" errors when starting Firefox. I did a full uninstall, then attempted to install the new version, I still get the same error during the install.

I am seeing the message that Updates are being managed by my organization: This my computer and NO Organization manages my updates! I may have paused them while updating my OS early this week. Now running Linux Mint 21.3I am seeing the message that Updates are being managed by my organization: This my computer and NO Organization manages my updates