I-Firefox Community Forum

Hello,

My little brother signed me out of my mozilla account while trying to login to his school account using my computer yesterday. Now, even after signing his account out AND removing his account entirely from my firefox, I'm unable to login using my credentials on the "original profile" which is what I've always used. This is the message I get when trying to login:

This profile was previously synced to a different account To keep your data organized and secure, each Firefox profile can only be synced to one account. To sign in using (email)@gmail.com, create a new profile.

He wasn't even able to fully login with his account, and even after completely removing his account from my firefox (as far as I know) I'm not able to sign into the original profile at *all*, even though that's what I've always used. Does anyone have a solution for this?

Hi all, I used to run two Firefox instances on the same computer, each one using a different account (as I mentioned in the Subject), but I don't remember how I managed this, so now that I moved to a new computer I can't reproduce it! Thanks for helping, if anyone knows. Regards, Mike

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 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?

With the profile system, which I just used to try and fix another problem. Deleting them doesn't work I've tried manually deleting the profiles as well but they still show up in the UI and it just recreates the folder again if you try to delete it or open it. If you use the UI to try and delete it the instance and page it opens is simply blank. And now the profile I'm trying to delete isn't open. I'm trying to delete it from "original profile" and when I do it opens the a new instance of firefox with the profile I'm trying to delete with in the address bar: about:deleteprofile but the screen is empty.

I had a problem where FF 140.0 would not update, and in trying to get FF yo update, I used a re-install tool to which I was pointed in my problem report. This caused FF to wipe out my configuration, and I lost all my windows and tabs. I have gone to

    \Appdata\Roaming\Mozilla\Firefox\Proifiles\abnfpged.default

cleared all of the data therein, and restored that directory from a backup I made last Monday. But I cannot get FF to use that directory. "about:profiles" shows only two profiles, but the Profiles directory has five profiles:

03/10/2026 09:39 AM <DIR> qf00ka5x.default 03/10/2026 09:39 AM <DIR> v842ceue.default-release 04/11/2026 09:16 PM <DIR> .. 04/11/2026 09:16 PM <DIR> . 04/12/2026 03:08 PM <DIR> abnfpged.default 04/12/2026 06:29 PM <DIR> jdfj91sd.default-release-1775960183850 04/12/2026 06:48 PM <DIR> f1jq4mlq.default

Only the profiles beginning with "j" and "f1" are seen in the "about:profiles" screenshot I have attached. And I have attached a screenshot of my profiles.ini file. Also, in the abnfpged.default directory I restored, where is the list of all of my open windows and tabs? FF used to keep that in a sessionstore.jsonlz4 file, but that file is only written when FF closes. I tried to save a copy when I was having problems, but I stored the copy in the same directory, which FF changed during the re-install process. Here is my profiles,.ini file:

[Install308046B0AF4A39CB] Default=Profiles/jdfj91sd.default-release-1775960183850 Locked=1

[Profile1] Name=default IsRelative=1 Path=Profiles/f1jq4mlq.default

[Profile0] Name=default-release IsRelative=1 Path=Profiles/jdfj91sd.default-release-1775960183850

[Install641D10338ABA448D] Default=Profiles/abnfpged.default Default=1 IsRelative=1 Locked=1

[General]

StartWithLastProfile=1

Version=2

[BackgroundTasksProfiles] MozillaBackgroundTask-308046B0AF4A39CB-defaultagent=lnvi5jn5.MozillaBackgroundTask-308046B0AF4A39CB-defaultagent

I have not worked with the ;profiles.ini file in many years, as my FF configuration has not had problems. Thanks.

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.

I was interested in seeing how the profiles worked so I clicked yes to creating one, but once I set another one up I realised I would have to use a separate Mozilla account on it and I would prefer to keep everything on one browser and account. I tried to delete the profiles but it said it would delete all my bookmarks and data, is there any other way to hit undo or something and go back to the way it was before (without profiles)?

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 have a folder/subfolder, Old Firefox Data/ukn05f6l.default-release, on my desktop created 11/30/2024.

Any ideas what it is? It is huge...940mb.

Can I delete it?

Thanks

Fire Fox - This profile was last used with a newer version of this App - Create a new profile.

After logging into my account, I saw a Fire Fox page showing new features. Upon downloading Fire Fox, I saw the the above message. I didn't want a new profile, but there wasn't an option to close the window and to just continue to use the newer version that was already installed ???

I tried Control / ALT / Delete . Upon restarting it showed the same message! I uninstalled Fire Fox, which surely has not helped things.

Am I able to restore the profile from the "newer version"? Otherwise, I will probably have to setup Fire Fox from scratch and have lost all bookmarks.

Thanks so much for your assistance. Myles

I am not a native English speaker, so I used translation. Please excuse any awkward phrasing. I previously updated my Firefox to version 150, but my tabs kept crashing roughly every 5 minutes. To solve this, I tried installing the Firefox ESR version. However, my profile had already been upgraded to the new version format, so ESR could not read my data. I then reinstalled version 150, but now I'm having profile issues again. I can access and launch my old profile through about:profiles, but I can't seem to save it directly as the default profile. I don't want to have to repeat this process every time I restart the browser. Is there a way to transfer all my data (bookmarks, saved passwords, add-ons, settings, etc.) to a new profile that works with the current version? Or, can I downgrade my profile so that ESR can read it? I have tried copying the files from %APPDATA%\Mozilla\Firefox\Profiles, but it didn't work after many attempts. Please help me. I really don't want to set everything up from scratch again. Thank you!

So I have a bunch of Firefox profiles I want to set up a new profile and I want to set up the profile switching with in that profile perhaps by creating a bunch of profiles from the about profiles page and then replacing those profiles with the old ones as I don't see a way to just import old profiles in the UI. How do I go bout doing that like copy and move exactly what exactly where.

I imported my profiles from another machine to a new laptop. Now the profiles all work and I can launch into them using the shortcuts with -p "[name]" this now brings up the old wizard rather than launching directly into the profile, and the new profile manager does not see them at all.

about:profiles sees them properly.

The profiles were imported by using about:profiles to make new black profiles, then copying in the data as from the support article: http://mzl.la/1xKrFsk

Many thanks in advance for the help.

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 want to restore a previous profile which I can see on File Explorer, but no previous profiles appear on the About Profiles page. How can I access this previous profile?

I'm a bit puzzled here. Initially, I tried to use the new built-in VPN for only a single domain. That doesn't work at all. Until it does, I tried to get it through other ways. Containers don't work, private windows neither, they both just inherit the global VPN setting.

So I moved on to profiles. The web found me a Mozilla support topic that suggested to open about:profiles and create a new one. Did that, opened a window for it, but couldn't get it to reopen on any easy path, just through opening about:profiles and clicking one of the many buttons again.

Then I found another description that used the "Profiles" menu. Never seen that before (probably because the menu bar isn't visible by default). Created a new profile there, too, and opened it. After restarting Firefox, all was gone! My original profile with everything was totally inaccessible, like a full data loss. Google search AI in a Chrome browser helped me out and explained what I need to do (in about:profiles, select the old one as default, then restart) to get my environment back. After that I deleted all newly created profiles and then their directories again.

Started over with a new "new" profile and continued there. Now I wanted to activate the VPN in there. It asked me to log in again, which was a good sign because finally I got a Firefox window that didn't know about the other window. But then the next failure: I couldn't log in with my credentials because that profile was already used in the other window/profile. Again, they're not completely separated from each other and there's some hidden link between them.

So, do I need a new Firefox/Mozilla account only for a separate Firefox profile? I can happily use my one account on different devices but not on the same device? Can I unlink the main profile from my account again? I don't see a logout button anywhere, I'm just logged in invisibly.