Firefox Community Forum

Mozilla made an update of my Firefox installation on my Win11 laptop. all my password disappeared as well as my history and bookmarks.

I have now a virgin installation and is starting from scratch.

Now I get this error message: "This profile was last used with a newer version of this application. Please create a new profile." I deleted met shortcut and I opened Firefox by using Windows search. Now I see 4 profiles! I think I do not need to create a new profile. Maybe delete 3 of them ? What to do ? And, how?

Yes, I'd like to use the same account on both of my profiles.

I understand that for some users, this may be confusing.

In my case, the only reason for different profiles is that I need to use a Proxy Server for some websites, and no proxy for other websites. Manually switching proxy settings is painful, and doing so causes traffic for my other tabs/windows to go to the proxy, which I do not want.

I have a main (set of) windows (and its tabs) going straight to the internet, then I have a separate window (and its tabs) configured to go through a proxy (SOCKS5 in this case). I want all other settings, bookmarks, passwords, etc. to be identical to both. I end up having to logout of my main profile, log into the other profile to sync settings, log out of there, and log back into my main profile.

Is there a valid technical reason why an account on the same FireFox installation cannot be shared between two profiles?

I can do this on multiple computers (same account, different computers/profile), seems odd it is restricted to not allow on the same computer.

I have an alternative solution: Install FireFox natively, then install FireFox as AUR or FlatPak, but not sure this will collide as this both uses the same profile directory. Hum...

Wayne

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)

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?

Before i got the Profiles update that rolled out relatively recently, i created another firefox profile from the "about:profiles" page. I do not see this second profile in the new Profiles tab in the menu in my default profile. Is there a way to transfer the profile, maybe mess with the files and the folder of firefox, so i will be able to switch profiles from the Profiles tab, and not go through "about:profiles" every time? or just create a new profile and tell me how to transfer the data, where to find the existing one thanks.

HI there,

Glad you folks have included an update to the 'profiles'. However, I'm having trouble with it. I previously created two profiles using 'about:profiles' function. However, only of them has mapped on to the new profiles feature. When I try to add a profile in the new way to do it, I can only create a new one, I can't transfer a pre-existing.

See attachments. One shows the new profile manager with the 'work' profile. The second shows the 'about:profiles' with both 'work' and 'life'. How to I add 'life' to the new profile manager?

I have previously made additional profiles on 'about:profiles', now Firefox has added an integrated profile manager accessible by clicking my profile on the top right. My old profiles are not available on this profile manager, but they are still available on 'about:profiles', so how can I transfer them without having to remake new ones?

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.

Hi,

When I opened Firefox today, it asked me which profile I'd like to use. I named one Katy and then continued. Now, I can't see any of my bookmarks, none of my passwords are saved, none of my sites recognized. I've been using Firefox for years. Everything I have is saved there. I just want my old stuff back. I'm signed in on my account, but can't see another profile that I can choose. My phone still has all the passwords and bookmarks from before but I I can't see what profile I'm signed in under. Can anyone help?

Thank you!

Katy

Hello, I have two profiles, one for work and one personal. I used two different email addresses for them. How can I merge these together for the new profile management?

new firefox update today plus windows update - get message "The bookmarks and history system will not be functional because one of Firefox's files is in use by another application. Some security software can cause this problem." Have tried to restore - no luck. Other bookmarks - empty.

Lost all bookmarks

Hi, I do not understand the new profile management feature of Firefox and how it relates to sync. I am logged into my Mozilla account that syncs bookmarks, and I use the default profile that I renamed to "personal". When I switch to a newly created "work" profile, I am no longer signed in.

Will the new profiles "personal" and "work" be synced to my account once I log on to both? I am using Firefox on several PCs and I don't want to recreate profiles such as "personal" and "work" on all the PCs manually?

Thanks for a reply.

As the title says, when i go to about:support, and click the open profile folder, i wanted to install a customization to allow me to edit the default tab background, but for some reason i do not have admin privileges in that folder, i can't access anything, i can't edit anything nor create a new folder, even rename it. It says that my own computer does not have admin privileges inside that folder.

I've used Firefox as my default for years and years. Yesterday I got some popover telling me I had to create a new profile or I'd lose all my Firefox data, history, bookmarks, etc. It would not let me avoid this. So I did. Still lost all my history, started over. Today it's doing the same thing. What's up? I don't want to move to Chrome.

opened firefox saturday and screen was totally different than what i had. guess it updated, but not returned to my profile. have tried to open my profile and succeeded, but can't get it to come on automatically when i open firefox again. how do i open the profile i want and then keep it opened?