Firefox Community Forum

I have Firefox installed on both my desktop and my laptop. On my laptop, I am able to create and manage profiles; however, on my desktop, there is no option available in the menu (the hamburger menu) to do so.

I have verified that both devices are running the latest version of Firefox, which includes the profile management feature, but I am still unable to access it on my desktop.

I was positively surprised recently when the new Firefox profile manager (about:profilemanager) was introduced. https://www.tech2geek.net/how-to-use-the-new-updated-profile-manager-in-firefox-2025/ is an article about that.

However, I thought it's just a new visual UI with an in-browser switcher for the existing profiles (that I already had setup). However, it does not appear so.

The differences I see:

1. 1. 1. old profile management

• was managed by `about:profiles` or when starting FIrefox with `-P`
• is saved in `~/firefox` and the `profiles.ini` clearly and quite obviously mentions them there, so it's easy to manage them.

I also found this old support article: https://support.mozilla.org/en-US/kb/profile-manager-create-remove-switch-firefox-profiles

1. 1. 1. new profile management

• automatically asks on startup if more than one profile exists
• is managed by `about:profilemanager` or with the Firefox burger menu
• seems to be saved in `~/.mozilla/firefox/Profile Groups` (Linux path here) in some .sqlite files, and I do not quite understand the format. Not mentioned in `profiles.ini`.
• also, when you change something here (even like opening a profile?), you cannot open `about:profiles` anymore, because it says "Some Firefox process has made changes to your profile, […] you need to restart Firefox", only after a restart further changes would be possible, which I find quite confusing but it also indicates somehow the features belong together?

And this seems to be the new one: https://support.mozilla.org/en-US/kb/profile-management#w_whats-the-difference-between-profiles-and-multi-account-containers

1. 1. Questions

• What are the differences here (I may have missed)?
• How can the new profile feature save so few files? Is it technically called "profile groups"?
• And the most important: How can I migrate an old profile? (In order to use the new features and GUI etc. I quite like)

Unimportant and mildly disruptive issue: I've been using the about:profiles method to maintain separate profiles. I am aware that this is distinct from the new way to manage profiles (about:profilemanager; https://support.mozilla.org/en-US/questions/1543697 ).

I normally use my default profile (let's call it profile A) to open other profiles (of which there are 6 + a Nightly profile).

However, recently I've noticed that if I open another profile (B) from profile A: Refreshing profile A's about:profiles makes it inactive, with the "Another copy of Firefox has made changes to profiles" error. Now, B's about:profiles correctly displays the different profiles, and I can launch more profiles from here. But A is still shown as the default profile. I've tried this with a few other profiles (C, D), but even with those open, B still seems to have the functional about:profiles page.

Is there any way to reset this, i.e. to make A's about:profiles functional even when profile B is launched?

Edit: I think this is because profile B has the new profile manager enabled, and under this, B is the original profile. I tried setting browser.profiles.enabled to false in the about:config settings but this doesn't seem to help. Oh well!

I recently reinstalled Debian 13 on my workstation. This included installing Firefox-esr from the Debian repositories so the version before and after the reinstall is the same. Despite this, Firefox refused to start until I created a new profile - insisting that my profile was from an older version.

To add insult to injury, it offers a method to import data from Chromium (which I use rarely) but not from a previous Firefox profile.

Firefox Sync works so far as it goes, but not everyone wants to use it. Importing from a local profile should be easier to implement than remotely syncing - especially given that Firefox clients may not be the same on different devices.

And, of course, the initial point is that Firefox should accept a user profile when it was created by the same version. After all, when I upgrade Firefox on Debian, I'm not required to create a new profile. Why should I be forced to do it when I reinstall the same version?

I have a bunch of profiles set up via "about:profiles". Some of these are associated with different Mozilla accounts, some are not. Today, I wanted to rearrange those profiles to put some older profiles that I do not use as often lower on the page than more recent profiles. I thought I remembered there being an overview text file that included a number for each profile, the folder that profile's information was stored in, etc. When I went looking for that file, I could not find it, so I went looking for help articles and discovered that there is a new profile management tool.

When I tried using the new profile manager via "about:profilemanager", none of my current profiles are visible, so I cannot use that tool to reorder my profiles.

I would be grateful if you could point me to an article explaining how to reorder the profiles in "about:profiles". If that is not possible, I would appreciate a help article explaining the rationale for making these two uses of the word "profile" distinct, the ways in which these profiles are different from each other, and how to transfer settings from the older version to the newer version. I have everything set up just the way I like it within my current profiles and really do not want to have to recreate them from scratch...

I switched to Firefox a few months ago and I've been using the "about:profiles" page to mimic chrome's profile feature. I have 3 profiles, each with their own Mozilla account. How can I migrate these to the new profiles system?

I have an account with Chewy. When I try to access the link to "My Pet" I receive this message:

400 Bad request Your browser sent an invalid request.

I don't understand why or how to correct it.

Starting with Firefox 141, I noticed the profile folder is locked down by Mozilla by way of folder permissions, to the extent that I (as administrator) cannot even take ownership of the folder. Even after I completely uninstalled Firefox and restarted my computer I can't take ownership of the folder, nor can I delete it - access is simply denied. I have to literally boot up with a Linux Live distro to be able to delete it. This is invasive and NOT OK!!

I work with multiple profiles that require backups and be copied. I also have a 'master profile' which is set up to co contain all my settings and addons - when I require a new profile I simply copy it over and voila. Not even this is possible anymore, as Mozilla has locked down the entire folder tree, I can no longer copy a new profile into C:\Users\*USER*\AppData\Roaming\Mozilla\Firefox\Profiles.

I also cannot copy existing profiles (and therefore also not able to backup) out of C:\Users\*USER*\AppData\Roaming\Mozilla\Firefox\Profiles - access denied. This is uncalled for by Mozilla. I have complete removed Firefox from my computer, including registry entries, and even after that I'm still denied access and cannot even delete C:\Users\*USER*\AppData\Roaming\Mozilla.

The only solution to to any of the above issues is to either reboot into Windows Safe Mode or bootable media of another OS. But this is totally impractical - Mozilla cannot expect of me to stop all my work and restart my PC every time I need to perform any of the above mentioned issues.

This is highly invasive by Mozzilla - to not even be able to delete a profile folder without any trace of Mozilla on my computer???? Come on, FIX THIS !!!

Will Mozilla please provide the solution?

Every other day, I open FireFox and may get the following error: XULRunner - This profile was last used with a newer version of this application. Please create a new profile. Also, this error may come up while I already have had FireFox open for a while. Once this error comes up, I check the version, and sometimes the version is older than what it was, meaning, FireFox reverted back to an older version on it's own. I created a new profile, but the error comes back. I removed FireFox and all folders, and the error still comes back. There is nothing I can do to stop the error from showing up again. See attached images. I am on Windows 11 23H2, all windows updates caught up, and the current FireFox browser version is 138.03.

Hi,

I take a look to forums and docs but didn't find answer to it : just found informations about the use of firefox -P

Is there a way to change the defaults profile path.

For example, in the profiles.ini :

Name=default IsRelative=1 Path=Profiles/be7er9lz.default Default=1

this is a relative path referring to %appdata%\Mozilla\Firefox\[PathVariableValue]

Is there a way to change a config file or config to customise the path for all users a windows computer ?

For example :

setting this variable to \\nameofserver\Firefox\

will made all relatives profiles looking for : \\nameofserver\Firefox\[PathVariableValue]

without this option, I should be obliged to edit all users profiles.ini to change path to absolute

Thanks for your help

ludovic

I’m running into a limitation with Firefox profiles involving the original Profile Manager (about:profiles) and the new Profiles menu in the toolbar.

I previously created multiple profiles using the original Profile Manager (about:profiles), for example profiles A, B, and C. These profiles still function normally and can be launched through about:profiles, but they do not appear in the new Profiles menu in the toolbar.

I also tried using the “Copy this profile” option available from the new Profiles menu. This made it clear that the feature does not work with profiles created via about:profiles. For example, when I open profile A, I expected that I could use “Copy this profile” to copy profile A into an existing profile like profile B (which was also created using about:profiles). However, this is not possible. Profiles A, B, and C remain isolated from the new Profiles menu and cannot be accessed, copied, or managed through it.

At the moment, profiles created with the original Profile Manager (about:profiles) can only be accessed through that manager and cannot be transferred into the new Profiles menu in the toolbar.

Is there an official fix or a workaround that achieves the same result—specifically, transferring or integrating all existing profiles created with the original Profile Manager (about:profiles) into the new Profiles menu accessible from the Firefox toolbar?

I opened up Firefox just now to find that my two profiles currently in use are completely inaccessible. I was faced with a "Create Profile" dialogue that launched me into a brand new profile with none of my settings, keybinds, cookies, extensions, anything. Despite this, I know for a fact that my old profiles are *still* there. As you can see my profile folders are right there, with all their data intact as far as I can tell from inspecting their contents, yet they are not accessible from the about:profiles.

Please help me. What is happening with the profile manager? How do I access those old profiles?

I just tried creating a new profile in Nightly, and I received the "Approve sign-in to Firefox" email with a code, twice, but the profile page kept saying that my email bounced or something. Now it's saying it's locked.

With the new update came profiles, which is pretty useless for me. However, it bugs me that the firefox icon on the taskbar now has the profiles' star on it. Is there a way to remove this?

The article explaining why one should not downgrade ignores a critical reason why one needs to downgrade and that is when it turns out that the new version breaks an existing website!

I got bitten by this when Firefox "upgraded" me to V143 after which point the ticket system I use to support my customers stopped working. That same ticket system continues to work fine in Safari, Edge, Chrome and Brave, etc.

Worse, when one does try to downgrade, the old profile gets removed which means you lose EVERYTHING you had (tabs, bookmarks and presumably all the settings and saved passwords, etc). You need to be keeping the old profiles around so that they can be accessed again should someone NEED to downgrade. Fortunately I was able to use Time Machine to recover the old profile --- but somebody just didn't think this through.

Much as I have loved Firefox over the years, I'm starting to feel that it's time to give up on it and move to something else.

Turning off automatic updates is not a solution because eventually one will choose to upgrade manually and most people won't remember to make a copy of their existing profile. Should one then encounter a problem, you're back to square one

Very disappointing .

This afternoon, I clicked on a link from an email and for the first time got a choose a profile pop-up. I do not want this; I have read info on Mozilla and elsewhere about its purpose but it doesn't say how to just stop the pop-up - there should be an option just stop the pop-up because I don;t want to have to choose amongst options. I have started copy-pasting the links in emails and going to Chrome and will seriously have to reconsider using Firefox of this continues. I don't want to have to type about:config or anything - this should have been an opt out or opt in thing and I want out. Thank you for your help.

I made the mistake to following Mozilla's advice on why my tabs stopped coming back after I closed out, despite the fact that I had that selected in my settings. Now I'm stuck with an "Old Firefox Data" folder on my desktop and I can't remove it because I need administrator privileges -- but it's my personal PC. WTF